Article

Discussion

A diagnosis of lichen sclerosus (LS) was made based on clinical and dermoscopic features, followed by confirmation with histology. The patient’s presentation included typical signs and symptoms of LS: itching, burning, intermittent bleeding, perianal hemorrhage, fusion of the clitoral head, and fissures. Other presentations can include dyspareunia, erosions, and excoriations; however, these symptoms and signs were not reported or seen in this patient.

LS typically affects the anogenital region and has 2 peak incidences: in preadolescent teens and during the fifth to sixth decade of life.¹ This patient presented with a case of extragenital LS, which is less common than the classic presentation of LS that affects the genitals. This variant’s epidemiology differs, as it is less common in children and more common in postmenopausal women.² Extragenital LS presents as white, atrophic plaques with a predilection for sites including the trunk, breasts, upper arms, and sites of physical trauma, with symptoms of dryness and pruritus. Over time, the papules can coalesce and form ivory, scar-like papules or plaques with a wrinkled surface. In advanced stages, telangiectasia or follicular plugging can be present, along with flattening of the dermal-epidermal junction. This flat interface is fragile and can result in bullae that may become hemorrhagic.

Cutaneous squamous cell carcinoma (SCC) may infrequently arise from LS, similar to other chronic inflammatory dermatoses.³ Lichen planus is typically not associated with an increased risk of SCC, except in the oral and hypertrophic variants. However, LS may be considered a premalignant process, and many vulvar SCC cases are noted to have adjacent LS lesions.³

Autoimmune and genetic factors contribute to the pathogenesis of LS. Extracellular matrix protein 1 (ECM1) binds molecules of the basement membrane zone and dermis, contributing to the structure and integrity of skin. Autoantibodies against ECM1 and other antigens of the basement membrane zone, including BP180 and BP320, were found in LS.² HLA-DQ7 major histocompatibility complex class II antigens have been associated with LS.¹

On histologic examination, the epidermis of LS is atrophic with hyperkeratosis. The dermis shows homogenization and sclerosis of superficial collagen with a band-like lymphocytic infiltrate below the sclerosis. The basal layer is thickened, showing basal cell vacuolization and hydropic degeneration.⁴

First-line treatment for genital and extragenital variants of LS is high-potency topical steroids for 3 months or until the skin texture and color resolve (ie, clobetasol 0.05% cream or ointment). The second-line treatment is a topical calcineurin inhibitor. These treatments are used for management. They are not cures for LS, as relapse is possible after the initial treatment course is completed. Adverse effects of high potency topical steroids are skin burning, skin atrophy, and fragility, telangiectasia. The adverse effects of topical calcineurin inhibitors are stinging and burning on application.

Other Diagnostic Considerations

Inverse psoriasis (IP) is a variant of psoriasis that presents as erythematous, well-demarcated plaques with minimal scale in intertriginous areas and flexural surfaces. Localized dermatophyte, candidal, or bacterial infections can trigger IP.⁵ It occurs in about 3% to 7% of patients with plaque psoriasis and is thought to form due to koebnerization via mechanical friction of flexural zones.⁶ The patient described in this case did not have IP because IP would be more likely to present as a well-demarcated erythematous plaque rather than a patch.

Histologically, IP shows regular psoriasiform acanthosis and hypogranulosis of the epidermis, Munro microabscess, spongiform pustules of Kogoj, dilated tortuous dermal vessels, and thinning of the suprapapillary plates.⁵

Lichen planus pigmentosus-inversus (LPPI) is also known as lichen planus pigmentosus—intertriginous variant. This variant of lichen planus pigmentosus presents as multiple gray to dark brown macules and patches with poorly defined borders in a linear distribution limited to intertriginous areas, flexural surfaces, or following the lines of Blaschko.⁷ About 20% of cases present with frontal fibrosing alopecia. It is most common in individuals with intermediate and darker skin pigmentation, has a higher prevalence in females, and typically occurs within the third and fifth decades of life. Friction is a common trigger of LPPI.⁷ A diagnosis of LPPI is incorrect because the lesions would present as gray to dark brown macules, as opposed to the shiny white atrophic thin papules with surrounding pink and purple patches seen in this case.

Histologically, while both LS and LPPI share band-like lymphocytic infiltrate and basal cell vacuolization, findings in the dermis differ. LPPI shows melanophages and prominent melanin incontinence, while LS shows homogenization and sclerosis of superficial collagen.^1,8 LPPI also shows absence of compensatory keratinocyte proliferation.

Morphea is an inflammatory disease that affects the dermis and subcutaneous fat, resulting in sclerosis that appears scarlike. Its prevalence increases with age and has a 4:1 prevalence in females, with the plaque type being the most common variant. ⁹ The typical presentation of plaque-type morphea is an insidious onset of asymptomatic, slightly elevated, erythematous or violaceous, slightly edematous plaques with centrifugal expansion. The center of the plaque may become sclerotic and indurated, acquiring a shiny white color with a peripheral “lilac” ring. Trunk and upper extremity involvement is common. Morphea is associated with increased antisingle-stranded DNA, antitopoisomerase IIa, antiphospholipid, antifibrillin-1, and antihistone antibodies. Triggers of morphea are believed to be localized insults to the skin, including mechanical trauma, injections, vaccinations, and irradiation.⁹ This answer is incorrect because the patient’s lesions were pruritic and had genital involvement, which are not typical of morphea. Morphea can be differentiated with based on symptoms (lack of pruritus, pain, burning), morphology of lesions (induration versus atrophy), dermoscopy (fibrotic beams with less scale and hemorrhage vs keratotic follicular plugs), and histopathology (depth of inflammation in superficial and deep dermis).

Histology of morphea can differ based on the stage, whether the lesion is sampled in the inflammatory margin or central sclerosis, and the depth of affected skin. At the inflammatory margin, vascular changes, including endothelial swelling and edema, are present, as well as CD4+ T cells, eosinophils, plasma cells, and mast cells surrounding smaller blood vessels. In late stages, the inflammatory infiltrate is no longer present, the epidermis appears regular, and there is a flattened dermal-epidermal junction. Distinct features include homogenous collagen bundles that replace many dermal structures, with atrophic eccrine glands that appear “trapped” in the thickened dermis, and homogenized and hyalinized subcutis.⁹

Mycosis fungoides (MF) is the most common type of cutaneous T-cell lymphoma and presents as annular, erythematous or hypopigmented patches and plaques with fine scale and tumors on the buttocks and sun-protected areas of the limbs and trunk. Lesions can appear with prominent poikiloderma or atrophic or lichenified skin.¹⁰ It is most common in males of African descent aged 50 to 55 years. The etiology is largely unknown but believed to be multifactorial. This answer is incorrect because the lesions in this patient appeared more atrophic, were less well demarcated, and lacked the scale that would be present in MF.

On histology, both LS and MF show band-like lymphocytic infiltrate, however MF lacks the homogenization and sclerosis of superficial collagen that is present in the dermis of LS. Also, MF demonstrates epidermotropism of atypical lymphocytes forming Pautrier microabscess.¹⁰

Primary Care Role

Primary care physicians can diagnose and treat LS. Referral to dermatology is not mandatory. Note that topical steroids can be used daily for up to 12 weeks. In LS, early treatment is associated with improved outcomes and minimizes the risk of irreversible skin changes.¹¹ Follow-up during the treatment period is recommended to monitor subjective and objective response to treatment. Follow-up after the initial treatment is recommended since LS is typically chronic, can relapse, and SCC can infrequently arise from LS lesions.¹¹

Discussion

A diagnosis of lichen sclerosus (LS) was made based on clinical and dermoscopic features, followed by confirmation with histology. The patient’s presentation included typical signs and symptoms of LS: itching, burning, intermittent bleeding, perianal hemorrhage, fusion of the clitoral head, and fissures. Other presentations can include dyspareunia, erosions, and excoriations; however, these symptoms and signs were not reported or seen in this patient.

LS typically affects the anogenital region and has 2 peak incidences: in preadolescent teens and during the fifth to sixth decade of life.¹ This patient presented with a case of extragenital LS, which is less common than the classic presentation of LS that affects the genitals. This variant’s epidemiology differs, as it is less common in children and more common in postmenopausal women.² Extragenital LS presents as white, atrophic plaques with a predilection for sites including the trunk, breasts, upper arms, and sites of physical trauma, with symptoms of dryness and pruritus. Over time, the papules can coalesce and form ivory, scar-like papules or plaques with a wrinkled surface. In advanced stages, telangiectasia or follicular plugging can be present, along with flattening of the dermal-epidermal junction. This flat interface is fragile and can result in bullae that may become hemorrhagic.

Cutaneous squamous cell carcinoma (SCC) may infrequently arise from LS, similar to other chronic inflammatory dermatoses.³ Lichen planus is typically not associated with an increased risk of SCC, except in the oral and hypertrophic variants. However, LS may be considered a premalignant process, and many vulvar SCC cases are noted to have adjacent LS lesions.³

Autoimmune and genetic factors contribute to the pathogenesis of LS. Extracellular matrix protein 1 (ECM1) binds molecules of the basement membrane zone and dermis, contributing to the structure and integrity of skin. Autoantibodies against ECM1 and other antigens of the basement membrane zone, including BP180 and BP320, were found in LS.² HLA-DQ7 major histocompatibility complex class II antigens have been associated with LS.¹

On histologic examination, the epidermis of LS is atrophic with hyperkeratosis. The dermis shows homogenization and sclerosis of superficial collagen with a band-like lymphocytic infiltrate below the sclerosis. The basal layer is thickened, showing basal cell vacuolization and hydropic degeneration.⁴

First-line treatment for genital and extragenital variants of LS is high-potency topical steroids for 3 months or until the skin texture and color resolve (ie, clobetasol 0.05% cream or ointment). The second-line treatment is a topical calcineurin inhibitor. These treatments are used for management. They are not cures for LS, as relapse is possible after the initial treatment course is completed. Adverse effects of high potency topical steroids are skin burning, skin atrophy, and fragility, telangiectasia. The adverse effects of topical calcineurin inhibitors are stinging and burning on application.

Other Diagnostic Considerations

Inverse psoriasis (IP) is a variant of psoriasis that presents as erythematous, well-demarcated plaques with minimal scale in intertriginous areas and flexural surfaces. Localized dermatophyte, candidal, or bacterial infections can trigger IP.⁵ It occurs in about 3% to 7% of patients with plaque psoriasis and is thought to form due to koebnerization via mechanical friction of flexural zones.⁶ The patient described in this case did not have IP because IP would be more likely to present as a well-demarcated erythematous plaque rather than a patch.

Histologically, IP shows regular psoriasiform acanthosis and hypogranulosis of the epidermis, Munro microabscess, spongiform pustules of Kogoj, dilated tortuous dermal vessels, and thinning of the suprapapillary plates.⁵

Lichen planus pigmentosus-inversus (LPPI) is also known as lichen planus pigmentosus—intertriginous variant. This variant of lichen planus pigmentosus presents as multiple gray to dark brown macules and patches with poorly defined borders in a linear distribution limited to intertriginous areas, flexural surfaces, or following the lines of Blaschko.⁷ About 20% of cases present with frontal fibrosing alopecia. It is most common in individuals with intermediate and darker skin pigmentation, has a higher prevalence in females, and typically occurs within the third and fifth decades of life. Friction is a common trigger of LPPI.⁷ A diagnosis of LPPI is incorrect because the lesions would present as gray to dark brown macules, as opposed to the shiny white atrophic thin papules with surrounding pink and purple patches seen in this case.

Histologically, while both LS and LPPI share band-like lymphocytic infiltrate and basal cell vacuolization, findings in the dermis differ. LPPI shows melanophages and prominent melanin incontinence, while LS shows homogenization and sclerosis of superficial collagen.^1,8 LPPI also shows absence of compensatory keratinocyte proliferation.

Morphea is an inflammatory disease that affects the dermis and subcutaneous fat, resulting in sclerosis that appears scarlike. Its prevalence increases with age and has a 4:1 prevalence in females, with the plaque type being the most common variant. ⁹ The typical presentation of plaque-type morphea is an insidious onset of asymptomatic, slightly elevated, erythematous or violaceous, slightly edematous plaques with centrifugal expansion. The center of the plaque may become sclerotic and indurated, acquiring a shiny white color with a peripheral “lilac” ring. Trunk and upper extremity involvement is common. Morphea is associated with increased antisingle-stranded DNA, antitopoisomerase IIa, antiphospholipid, antifibrillin-1, and antihistone antibodies. Triggers of morphea are believed to be localized insults to the skin, including mechanical trauma, injections, vaccinations, and irradiation.⁹ This answer is incorrect because the patient’s lesions were pruritic and had genital involvement, which are not typical of morphea. Morphea can be differentiated with based on symptoms (lack of pruritus, pain, burning), morphology of lesions (induration versus atrophy), dermoscopy (fibrotic beams with less scale and hemorrhage vs keratotic follicular plugs), and histopathology (depth of inflammation in superficial and deep dermis).

Histology of morphea can differ based on the stage, whether the lesion is sampled in the inflammatory margin or central sclerosis, and the depth of affected skin. At the inflammatory margin, vascular changes, including endothelial swelling and edema, are present, as well as CD4+ T cells, eosinophils, plasma cells, and mast cells surrounding smaller blood vessels. In late stages, the inflammatory infiltrate is no longer present, the epidermis appears regular, and there is a flattened dermal-epidermal junction. Distinct features include homogenous collagen bundles that replace many dermal structures, with atrophic eccrine glands that appear “trapped” in the thickened dermis, and homogenized and hyalinized subcutis.⁹

Mycosis fungoides (MF) is the most common type of cutaneous T-cell lymphoma and presents as annular, erythematous or hypopigmented patches and plaques with fine scale and tumors on the buttocks and sun-protected areas of the limbs and trunk. Lesions can appear with prominent poikiloderma or atrophic or lichenified skin.¹⁰ It is most common in males of African descent aged 50 to 55 years. The etiology is largely unknown but believed to be multifactorial. This answer is incorrect because the lesions in this patient appeared more atrophic, were less well demarcated, and lacked the scale that would be present in MF.

On histology, both LS and MF show band-like lymphocytic infiltrate, however MF lacks the homogenization and sclerosis of superficial collagen that is present in the dermis of LS. Also, MF demonstrates epidermotropism of atypical lymphocytes forming Pautrier microabscess.¹⁰

Primary Care Role

Primary care physicians can diagnose and treat LS. Referral to dermatology is not mandatory. Note that topical steroids can be used daily for up to 12 weeks. In LS, early treatment is associated with improved outcomes and minimizes the risk of irreversible skin changes.¹¹ Follow-up during the treatment period is recommended to monitor subjective and objective response to treatment. Follow-up after the initial treatment is recommended since LS is typically chronic, can relapse, and SCC can infrequently arise from LS lesions.¹¹

Discussion

A diagnosis of lichen sclerosus (LS) was made based on clinical and dermoscopic features, followed by confirmation with histology. The patient’s presentation included typical signs and symptoms of LS: itching, burning, intermittent bleeding, perianal hemorrhage, fusion of the clitoral head, and fissures. Other presentations can include dyspareunia, erosions, and excoriations; however, these symptoms and signs were not reported or seen in this patient.

LS typically affects the anogenital region and has 2 peak incidences: in preadolescent teens and during the fifth to sixth decade of life.¹ This patient presented with a case of extragenital LS, which is less common than the classic presentation of LS that affects the genitals. This variant’s epidemiology differs, as it is less common in children and more common in postmenopausal women.² Extragenital LS presents as white, atrophic plaques with a predilection for sites including the trunk, breasts, upper arms, and sites of physical trauma, with symptoms of dryness and pruritus. Over time, the papules can coalesce and form ivory, scar-like papules or plaques with a wrinkled surface. In advanced stages, telangiectasia or follicular plugging can be present, along with flattening of the dermal-epidermal junction. This flat interface is fragile and can result in bullae that may become hemorrhagic.

Cutaneous squamous cell carcinoma (SCC) may infrequently arise from LS, similar to other chronic inflammatory dermatoses.³ Lichen planus is typically not associated with an increased risk of SCC, except in the oral and hypertrophic variants. However, LS may be considered a premalignant process, and many vulvar SCC cases are noted to have adjacent LS lesions.³

Autoimmune and genetic factors contribute to the pathogenesis of LS. Extracellular matrix protein 1 (ECM1) binds molecules of the basement membrane zone and dermis, contributing to the structure and integrity of skin. Autoantibodies against ECM1 and other antigens of the basement membrane zone, including BP180 and BP320, were found in LS.² HLA-DQ7 major histocompatibility complex class II antigens have been associated with LS.¹

On histologic examination, the epidermis of LS is atrophic with hyperkeratosis. The dermis shows homogenization and sclerosis of superficial collagen with a band-like lymphocytic infiltrate below the sclerosis. The basal layer is thickened, showing basal cell vacuolization and hydropic degeneration.⁴

First-line treatment for genital and extragenital variants of LS is high-potency topical steroids for 3 months or until the skin texture and color resolve (ie, clobetasol 0.05% cream or ointment). The second-line treatment is a topical calcineurin inhibitor. These treatments are used for management. They are not cures for LS, as relapse is possible after the initial treatment course is completed. Adverse effects of high potency topical steroids are skin burning, skin atrophy, and fragility, telangiectasia. The adverse effects of topical calcineurin inhibitors are stinging and burning on application.

Other Diagnostic Considerations

Inverse psoriasis (IP) is a variant of psoriasis that presents as erythematous, well-demarcated plaques with minimal scale in intertriginous areas and flexural surfaces. Localized dermatophyte, candidal, or bacterial infections can trigger IP.⁵ It occurs in about 3% to 7% of patients with plaque psoriasis and is thought to form due to koebnerization via mechanical friction of flexural zones.⁶ The patient described in this case did not have IP because IP would be more likely to present as a well-demarcated erythematous plaque rather than a patch.

Histologically, IP shows regular psoriasiform acanthosis and hypogranulosis of the epidermis, Munro microabscess, spongiform pustules of Kogoj, dilated tortuous dermal vessels, and thinning of the suprapapillary plates.⁵

Lichen planus pigmentosus-inversus (LPPI) is also known as lichen planus pigmentosus—intertriginous variant. This variant of lichen planus pigmentosus presents as multiple gray to dark brown macules and patches with poorly defined borders in a linear distribution limited to intertriginous areas, flexural surfaces, or following the lines of Blaschko.⁷ About 20% of cases present with frontal fibrosing alopecia. It is most common in individuals with intermediate and darker skin pigmentation, has a higher prevalence in females, and typically occurs within the third and fifth decades of life. Friction is a common trigger of LPPI.⁷ A diagnosis of LPPI is incorrect because the lesions would present as gray to dark brown macules, as opposed to the shiny white atrophic thin papules with surrounding pink and purple patches seen in this case.

Histologically, while both LS and LPPI share band-like lymphocytic infiltrate and basal cell vacuolization, findings in the dermis differ. LPPI shows melanophages and prominent melanin incontinence, while LS shows homogenization and sclerosis of superficial collagen.^1,8 LPPI also shows absence of compensatory keratinocyte proliferation.

Morphea is an inflammatory disease that affects the dermis and subcutaneous fat, resulting in sclerosis that appears scarlike. Its prevalence increases with age and has a 4:1 prevalence in females, with the plaque type being the most common variant. ⁹ The typical presentation of plaque-type morphea is an insidious onset of asymptomatic, slightly elevated, erythematous or violaceous, slightly edematous plaques with centrifugal expansion. The center of the plaque may become sclerotic and indurated, acquiring a shiny white color with a peripheral “lilac” ring. Trunk and upper extremity involvement is common. Morphea is associated with increased antisingle-stranded DNA, antitopoisomerase IIa, antiphospholipid, antifibrillin-1, and antihistone antibodies. Triggers of morphea are believed to be localized insults to the skin, including mechanical trauma, injections, vaccinations, and irradiation.⁹ This answer is incorrect because the patient’s lesions were pruritic and had genital involvement, which are not typical of morphea. Morphea can be differentiated with based on symptoms (lack of pruritus, pain, burning), morphology of lesions (induration versus atrophy), dermoscopy (fibrotic beams with less scale and hemorrhage vs keratotic follicular plugs), and histopathology (depth of inflammation in superficial and deep dermis).

Histology of morphea can differ based on the stage, whether the lesion is sampled in the inflammatory margin or central sclerosis, and the depth of affected skin. At the inflammatory margin, vascular changes, including endothelial swelling and edema, are present, as well as CD4+ T cells, eosinophils, plasma cells, and mast cells surrounding smaller blood vessels. In late stages, the inflammatory infiltrate is no longer present, the epidermis appears regular, and there is a flattened dermal-epidermal junction. Distinct features include homogenous collagen bundles that replace many dermal structures, with atrophic eccrine glands that appear “trapped” in the thickened dermis, and homogenized and hyalinized subcutis.⁹

Mycosis fungoides (MF) is the most common type of cutaneous T-cell lymphoma and presents as annular, erythematous or hypopigmented patches and plaques with fine scale and tumors on the buttocks and sun-protected areas of the limbs and trunk. Lesions can appear with prominent poikiloderma or atrophic or lichenified skin.¹⁰ It is most common in males of African descent aged 50 to 55 years. The etiology is largely unknown but believed to be multifactorial. This answer is incorrect because the lesions in this patient appeared more atrophic, were less well demarcated, and lacked the scale that would be present in MF.

On histology, both LS and MF show band-like lymphocytic infiltrate, however MF lacks the homogenization and sclerosis of superficial collagen that is present in the dermis of LS. Also, MF demonstrates epidermotropism of atypical lymphocytes forming Pautrier microabscess.¹⁰

Primary Care Role

Primary care physicians can diagnose and treat LS. Referral to dermatology is not mandatory. Note that topical steroids can be used daily for up to 12 weeks. In LS, early treatment is associated with improved outcomes and minimizes the risk of irreversible skin changes.¹¹ Follow-up during the treatment period is recommended to monitor subjective and objective response to treatment. Follow-up after the initial treatment is recommended since LS is typically chronic, can relapse, and SCC can infrequently arise from LS lesions.¹¹

Clinical simulation is a technique, not a technology, used to replace or amplify real experiences with guided experiences that evoke or replicate substantial aspects of the real world in a fully interactive fashion.¹ Simulation is widely used in medical education and spans a spectrum of sophistication, from simple reproduction of isolated body parts to high-fidelity human patient simulators that replicate whole body appearance and variable physiological parameters.^2,3

Simulation-based medical education can be a valuable tool for safe health care delivery.⁴Simulation-based education is typically provided via 5 modalities: mannequins, computer-based mannequins, standardized patients, computer-based simulators, and software-based simulations. Simulation technology increases procedural skill by allowing for deliberate practice in a safe environment.⁵ Mastery learning is a stringent form of competency-based education that requires trainees to acquire clinical skill measured against a fixed achievement standard.⁶ In mastery learning, educational practice time varies but results are uniform. This approach improves patient outcomes and is more effective than clinical training alone.^7-9

Advanced simulation models are helpful tools for neurologic education and training, especially for emergency department encounters.¹⁰ In recent years, advanced simulation models have been applied in various fields of medicine, especially emergency medicine and anesthesia.^11-14

Acute neurology

In acute neurologic conditions (eg, stroke, intracerebral hemorrhage, status epilepticus, and neuromuscular respiratory failure) clinical outcomes are highly time dependent; consequently, a reduction in treatment delays can improve patient care. The application of simulation methodology allows trainees to address acute and potentially life-threatening emergencies in a safe, controlled, and reproducible environment. In addition to improving trainees’ knowledge base, simulation also helps to enhance team skills, communication, multidisciplinary collaboration, and leadership. Research has shown that deliberate practice leads to a decrease in clinical errors and improved procedural performance in the operating room.^8,15 These results can be extrapolated to acute neurology settings to improve adherence to set protocols, thus streamlining management in acute settings.

Scenarios can be built to teach skills such as eliciting an appropriate history, establishing inclusion or exclusion criteria for the use of certain medications, evaluating neuroimaging and laboratory studies (while avoiding related common pitfalls), and managing treatment complications. Simulation also provides an opportunity for interprofessional education by training nurses and collaborative staff. It can be used to enhance nontechnical skills (eg, communication, situation awareness, decision making, and leadership) that further contribute to patient safety. 

Simulation can be performed with the help of mannequins such as the SimMan 3G(Laerdal), which can display neurologic symptoms and physiological findings, or live actors who portray a patient by mimicking focal neurologic deficits.^16,17 A briefing familiarizes the trainees with the equipment and explains the simulation process. The documentation and equipment are the same as that which is used in emergency departments or intensive care units. 

Once the simulation is completed, a trainee’s performance is checked against a critical action checklist before a debriefing process during which the scenario is reviewed and learning goals are assessed. Immediate feedback is given to trainees to identify weaknesses and the simulation is repeated if multiple critical action items are missed. (Figure).¹⁷

RESIDENCY TRAINING

Simulation training in stroke is mandatory in some residency programs for neurology postgraduate year (PGY) 2 residents.¹⁸ These simulations are a part of a boot camp for incoming neurology residents after completing an internal medicine internship. The simulation program is not standardized across various training programs. The European Stroke Organization Simulation Committee has published an opinion paper with a consensus of experts about the implementation of simulation techniques in the stroke field.^19,20 Residents participating in these mandatory programs are required to complete certification in the National Institutes of Health Stroke Scale (NIHSS) and the modified Rankin Scale, including a pretest that assesses their knowledge of acute stroke protocols prior to live simulation.¹⁷ A stepwise algorithm that incorporates faculty specialized in the field is used to evaluate and debrief the simulation.

Stroke vignettes are typically selected by the vascular neurology attending physician to cover thrombolytic therapy (indications and contraindications), mechanical thrombectomy, early arterial blood pressure management, anticoagulant reversal protocols, and management of thrombolytic complications (eg, neurologic worsening). Nursing staff is educated on the acute stroke protocol. Computed tomography (CT) and CT angiography scans are retrieved from teaching files. These are provided as live responses along with pertinent laboratory work, vital signs, and electrocardiogram tracings. Trainee performance is based on adherence to a critical action checklist, which includes (but is not limited to) identification of relative and absolute contraindications of thrombolytic treatments, estimation of NIHSS within 5 minutes of arrival, and consideration of candidacy for endovascular intervention.¹⁷

EVIDENCE FOR SIMULATION TRAINING

Simulations for acute ischemic stroke also improve cohesive teamwork to improve the door-to-needle and door-to-puncture time. A retrospective analysis involving first-year neurology residents at a comprehensive stroke center that compared patient cohort data before and after implementation of simulation training found that there was an improvement in door-to-needle time after implementation of stroke simulation training program by nearly 10 minutes.¹⁷ This was likely due to improvement in the comfort of the flow of management across multidisciplinary teams.

Discussing goals of care, communicating poor prognosis or complex decisions with distraught family members or patients requires practice. Simulation programs with video playback help focus on trainee’s body language, avoiding medical jargon and handling ethical dilemmas while adjusting the communication style to the patient’s personality.²⁰ Enhanced communication skills improve patient satisfaction, trust, and adherence to treatments, all of which lead to better outcomes.²¹

Simulation has been effectively used as a training tool for recognizing and managing acute neuromuscular respiratory failure. These scenarios emphasize the importance of obtaining a focused clinical history, performing key neurological assessments (such as neck flexion strength and breath counting), evaluating pulmonary function tests, and identifying when to initiate ventilatory support.²² In a study designed as a simulation-based learning curriculum for status epilepticus, there was an improvement in the performance of PGY-2 residents after completing the curriculum from a median of 44.2% at pretest to 94.2% at posttest.²³ In this curriculum, an emphasis was placed on the following: recognizing the delay in identification and treatment of status epilepticus; evaluating contraindications of certain antiseizure medication (ASM) based on history or laboratory work; giving first-line ASM within 5 minutes of seizure onset; airway and blood pressure assessment; suctioning the patient; use of second-line ASMs after first-line has failed; ordering a head CT and re-evaluating the case with postload ASM level; ordering a stat electroencephalography (EEG); and communicating the decision regarding patient disposition/level of care.²⁴

There is a growing need for well designed simulation education programs targeted at the management of disorders requiring acute neurologic care, including not only stroke and status epilepticus, but also traumatic brain injury, subarachnoid hemorrhage, neuromuscular respiratory failure, flare of multiple sclerosis, acutely elevated intracranial pressure, malignant cerebral infarction, deterioration of Parkinson disease, and brain death evaluation with family counseling.²⁵ This novel approach to teaching provides an opportunity to learn in addition to remediation with repetition of scenario and might be used for maintenance of recertification programs.

PROCEDURAL SKILLs

Perhaps one of the most studied uses for simulation in neurology is in procedural skills. This extends beyond neurology trainees and can include pulmonary critical care fellows, pediatric residents, and internal medicine residents receiving training in neurology-based procedures such as lumbar punctures (LPs). Other examples of neurology procedures and protocols in which simulation has been studied include fundoscopy, brain death evaluation, EEG interpretation in context of status epilepticus, and simulated stroke code responses. Additional procedures that lack research but may benefit from simulation-based training include the use of Doppler ultrasound and botulinum toxin injections practiced on mannequins.

Proficiency in LP procedural skills has been extensively studied by multiple institutions, with trainee levels ranging from medical students to fellows. One study in France enrolled 115 medical students without prior LP experience and randomized them to either a simulation or a control group.²⁶ Those in the simulation group received instruction using a mannequin, and those in the control group received clinical training through hospital rotations. Both groups received an email containing literature-based information on the procedure as well as a self-assessment questionnaire before participating in either educational program. 

The study showed that those students who received simulation training had a success rate of 67% on their first LP on a live patient compared with a success rate of 14% in those with traditional training. Students receiving simulation training required less assistance during the procedure from a supervisor and had higher satisfaction rates and confidence in their procedural skills.²⁶

Another study of 128 medical students at the University of Pittsburgh found that a hybrid LP simulation significantly improved students’ confidence and perceived skill in performing LPs, obtaining informed consent, and electronic order entry. For example, confidence with LP increased from 5.95% presimulation to 90% postsimulation, with 58.24% of students reporting an improvement from minimal or no confidence to average or better (P < .001). Similarly, the proportion of students who felt able to perform LP with minimal or no assistance rose from 0% to 38.57% (P < .001). Confidence and perceived skill in obtaining informed consent and electronic order entry also saw significant gains. Although real-world skill assessments were limited by low survey response rates, preceptor evaluations and follow-up surveys suggested that students who participated in the simulation were more likely to perform these tasks independently or with minimal supervision during clinical rotations.²⁷

Research on simulation training involving nonneurology residents is also encouraging. One study compared the LP skills of traditionally trained neurology residents (PGY-2 to PGY-4) to internal medicine residents (PGY-1) who underwent simulation on a mannequin.²⁸ The internal medicine residents first underwent a pretest on LP performance, watched an educational video, underwent an LP demonstration, and practiced on a mannequin with feedback. The neurology residents completed the checklist-style pretest and performed an LP on a mannequin. Internal medicine residents were found to increase their pretest scores from a mean of 46.3% to 95.7% following training, whereas neurology residents scored a mean of 65.4%. More than half of neurology residents were unable to identify the correct anatomic location or standard cerebrospinal fluid (CSF) tests to be ordered on a routine LP.²⁸

A pediatric resident study in Canada found that following simulation-based training, LP procedural skill improved in 15 of 16 residents tested, and PGY-1 residents showed a reduction in anxiety related to performing the procedure.²⁹

Virtual Reality

An additional tool for simulation is the use of virtual reality (VR) in combination with mannequins. A French study used videos of LPs on actual patients, from equipment set up to final CSF collection and termination of the procedure.³⁰ These videos included a 360-degree view of the procedure. The short video was administered through a VR device (the Oculus Go headset by Microsoft) or by a YouTube video (if VR was not desired).

Participants in the study watched the video then performed an LP on a mannequin. Those who used the VR option had minimal adverse effects (eg, low rates of cybersickness, blurred vision, nausea) and high satisfaction regarding their training environment.³⁰Another VR-based program is the vascular intervention system trainer, which allows clinicians to use endovascular devices and simulate procedures such as thrombectomies. VR simulation is used for trainees and to retrain experienced physicians in performance of high-risk procedures.³¹

Fundoscopic and Ultrasound Simulations

The AR403 eye stimulator device for fundoscopic examinations is a mannequin-based simulation.³² In a single-center, prospective, single-blind study of neurology and pediatric neurology residents, trainees were split into control and intervention groups, with the intervention group receiving simulator training. Both groups received video lectures on fundoscopy techniques. Pre- and postintervention measurements included knowledge, skill, and total scores on the skills assessment. Of the 48 trainees who participated, the intervention group demonstrated significantly higher increases in skills (P = .01) and total (P = .02) scores, although knowledge scores did not improve. The intervention group also reported higher comfort levels, higher confidence, and higher success rates.

Areas that would benefit from simulation training and development include ultrasound training, such as transcranial Doppler evaluation. In a national survey of residents in anesthesia and critical care, trainees reported that simulation was not frequently used in ultrasound training and that bedside teaching was more common. Interestingly, there was a discrepancy between the opinions of residents and program directors. The program directors felt simulation was in fact used (18.2% of program directors reported this vs 5.3% of trainees).³³

A new program, the NewroSim (Gaumard), is a computer-based model of cerebral perfusion that may be a useful tool in this setting. It can simulate blood flow velocities, including pathologic ones, both with a mannequin or without.³⁴

Another potential area for development is the use of mannequins to teach botulinum toxin injections for migraine, dystonia and spasticity in a training environment This is typically led by pharmaceutical representatives who are not necessarily clinicians. Residents and fellows may benefit instead from clinician-led education during their training programs.

Simulation in Patient Communication

Simulation provides a realistic environment for teaching rapid decision-making, leadership, and appropriate management of acutely ill neurologic patients; this includes the communication skills needed in response to neurologic injury.³⁵ Simulation can be particularly useful in situations involving brain death determination, where the communication techniques differ significantly from those used in shared decision-making. Simulation provides a low-stakes setting for clinicians to practice the process of brain death determination and communication, leading to improved confidence and knowledge.³⁶

In the context of acute neurologic emergencies, simulation exercises have been used to investigate the consistency of prognostication across a spectrum of neurology physicians. These exercises revealed that acute neuroprognostication is highly variable and often inaccurate among neurology clinicians, suggesting a potential area for improvement through further simulation training.³⁷

FUTURE DIRECTIONS

Simulation education in neurology can be directed towards learners at all levels, including medical students, residents, fellows, nurses, and medical technologists. In addition, simulation has great value to different disciplines, including emergency medicine, intensive care, and psychiatry. In our view simulation is not being used to full potential in neurology.

Simulation can be used to expose clinicians to rare pathology, play an integral role in competency-based evaluations, and serve as the foundation for simulation-based neurology curriculums, teleneurology simulation training programs, and team training for neurologic emergencies.³⁸Another under-recognized aspect of neurology education is teaching interpersonal communication and professionalism. A survey conducted at a neurology department (20 residents and 73 faculty respondents) asked about residents’ comfort level in performing a number of interpersonal communication and professionalism tasks.³⁸ While none of the residents said they were “very uncomfortable” with these tasks, only 1 resident reported being “very comfortable.” In addition, fewer than 50% noted that they had been directly observed by a faculty member while performing these tasks. The results prompted the facility to develop a simulation curriculum that including observation and feedback from 8 objective structured clinical examinations at a simulation center. A standardized professional simulated the role of a patient, caregiver, medical student, or a faculty member. Residents indicated in postsimulation surveys that it was very useful, and a majority voted for the activity to be repeated for future classes.³⁸

Simulation models may also provide a more objective method to evaluate neurology residents. Accreditation Council for Graduate Medical Education has provided Milestones that are used for assessment of neurology residents. Most of the programs rely on end-of-rotation faculty evaluations. These are subjective evaluations, rely on chance evaluations and may not reflect the exact caliber of a trainee in different clinical situations. Simulation models can serve as alternatives to provide an objective and accurate assessment of resident’s competency in different neurologic scenarios. 

In a study of PGY-4 neurology residents from 3 tertiary care academic medical centers were evaluated using simulation-based assessment. Their skills in identifying and managing status epilepticus were assessed via a simulation-based model and compared with clinical experience. No graduating neurology residents were able to meet or exceed the minimum passing score during the testing. It was suggested that end-of-rotation evaluations are inadequate for assigning level of Milestones.²⁴ To move forward with use of simulation-based assessments, these models need to be trialed more extensively and validated. 

Morris et al developed simulations for assessment in neurocritical care.³⁹ Ten evaluative simulation cases were developed. Researchers reported on 64 trainee participants in 274 evaluative simulation scenarios. The participants were very satisfied with the cases, found them to be very realistic and appropriately difficult. Interrater reliability was acceptable for both checklist action items and global rating scales. The researchers concluded that they were able to demonstrate validity evidence via the 10 simulation cases for assessment in neurologic emergencies.³⁹ It is the authors’ belief that the future of residents’ competency assessment should include more widespread use of similar simulation models. 

Finally, VR and augmented reality (AR) have shown promise in various fields, including neurology. In neurology, these technologies are being explored for applications in rehabilitation, therapy, and medical training. Ongoing research aims to leverage these technologies for improved patient outcomes and medical education. Virtual simulations can recreate neurologic scenarios, allowing learners to interact with 3-dimensional (3D) models of the brain or experience virtual patient cases. AR can enhance traditional learning materials by overlaying digital information onto real-world objects, aiding in the understanding of complex neuroanatomy and medical concepts. These technologies contribute to more engaging and effective neurology education.³⁹In a study of 84 graduate medical students divided into 3 groups, the first group attended a traditional lecture on neuroanatomy, the second group was shown VR-based 3D images, and the third group had a VR-based, interactive and stereoscopic session.⁴⁰ Groups 2 and 3 showed the highest mean scores in evaluations and differed significantly from Group 1 (P < .05). Groups 2 and 3 did not differ significantly from each other. The researchers concluded that VR-based resources for teaching neuroanatomy fostered significantly higher learning when compared to the traditional methods.⁴⁰

Clinical simulation is a technique, not a technology, used to replace or amplify real experiences with guided experiences that evoke or replicate substantial aspects of the real world in a fully interactive fashion.¹ Simulation is widely used in medical education and spans a spectrum of sophistication, from simple reproduction of isolated body parts to high-fidelity human patient simulators that replicate whole body appearance and variable physiological parameters.^2,3

Simulation-based medical education can be a valuable tool for safe health care delivery.⁴Simulation-based education is typically provided via 5 modalities: mannequins, computer-based mannequins, standardized patients, computer-based simulators, and software-based simulations. Simulation technology increases procedural skill by allowing for deliberate practice in a safe environment.⁵ Mastery learning is a stringent form of competency-based education that requires trainees to acquire clinical skill measured against a fixed achievement standard.⁶ In mastery learning, educational practice time varies but results are uniform. This approach improves patient outcomes and is more effective than clinical training alone.^7-9

Advanced simulation models are helpful tools for neurologic education and training, especially for emergency department encounters.¹⁰ In recent years, advanced simulation models have been applied in various fields of medicine, especially emergency medicine and anesthesia.^11-14

Acute neurology

In acute neurologic conditions (eg, stroke, intracerebral hemorrhage, status epilepticus, and neuromuscular respiratory failure) clinical outcomes are highly time dependent; consequently, a reduction in treatment delays can improve patient care. The application of simulation methodology allows trainees to address acute and potentially life-threatening emergencies in a safe, controlled, and reproducible environment. In addition to improving trainees’ knowledge base, simulation also helps to enhance team skills, communication, multidisciplinary collaboration, and leadership. Research has shown that deliberate practice leads to a decrease in clinical errors and improved procedural performance in the operating room.^8,15 These results can be extrapolated to acute neurology settings to improve adherence to set protocols, thus streamlining management in acute settings.

Scenarios can be built to teach skills such as eliciting an appropriate history, establishing inclusion or exclusion criteria for the use of certain medications, evaluating neuroimaging and laboratory studies (while avoiding related common pitfalls), and managing treatment complications. Simulation also provides an opportunity for interprofessional education by training nurses and collaborative staff. It can be used to enhance nontechnical skills (eg, communication, situation awareness, decision making, and leadership) that further contribute to patient safety. 

Simulation can be performed with the help of mannequins such as the SimMan 3G(Laerdal), which can display neurologic symptoms and physiological findings, or live actors who portray a patient by mimicking focal neurologic deficits.^16,17 A briefing familiarizes the trainees with the equipment and explains the simulation process. The documentation and equipment are the same as that which is used in emergency departments or intensive care units. 

Once the simulation is completed, a trainee’s performance is checked against a critical action checklist before a debriefing process during which the scenario is reviewed and learning goals are assessed. Immediate feedback is given to trainees to identify weaknesses and the simulation is repeated if multiple critical action items are missed. (Figure).¹⁷

RESIDENCY TRAINING

Simulation training in stroke is mandatory in some residency programs for neurology postgraduate year (PGY) 2 residents.¹⁸ These simulations are a part of a boot camp for incoming neurology residents after completing an internal medicine internship. The simulation program is not standardized across various training programs. The European Stroke Organization Simulation Committee has published an opinion paper with a consensus of experts about the implementation of simulation techniques in the stroke field.^19,20 Residents participating in these mandatory programs are required to complete certification in the National Institutes of Health Stroke Scale (NIHSS) and the modified Rankin Scale, including a pretest that assesses their knowledge of acute stroke protocols prior to live simulation.¹⁷ A stepwise algorithm that incorporates faculty specialized in the field is used to evaluate and debrief the simulation.

Stroke vignettes are typically selected by the vascular neurology attending physician to cover thrombolytic therapy (indications and contraindications), mechanical thrombectomy, early arterial blood pressure management, anticoagulant reversal protocols, and management of thrombolytic complications (eg, neurologic worsening). Nursing staff is educated on the acute stroke protocol. Computed tomography (CT) and CT angiography scans are retrieved from teaching files. These are provided as live responses along with pertinent laboratory work, vital signs, and electrocardiogram tracings. Trainee performance is based on adherence to a critical action checklist, which includes (but is not limited to) identification of relative and absolute contraindications of thrombolytic treatments, estimation of NIHSS within 5 minutes of arrival, and consideration of candidacy for endovascular intervention.¹⁷

EVIDENCE FOR SIMULATION TRAINING

Simulations for acute ischemic stroke also improve cohesive teamwork to improve the door-to-needle and door-to-puncture time. A retrospective analysis involving first-year neurology residents at a comprehensive stroke center that compared patient cohort data before and after implementation of simulation training found that there was an improvement in door-to-needle time after implementation of stroke simulation training program by nearly 10 minutes.¹⁷ This was likely due to improvement in the comfort of the flow of management across multidisciplinary teams.

Discussing goals of care, communicating poor prognosis or complex decisions with distraught family members or patients requires practice. Simulation programs with video playback help focus on trainee’s body language, avoiding medical jargon and handling ethical dilemmas while adjusting the communication style to the patient’s personality.²⁰ Enhanced communication skills improve patient satisfaction, trust, and adherence to treatments, all of which lead to better outcomes.²¹

Simulation has been effectively used as a training tool for recognizing and managing acute neuromuscular respiratory failure. These scenarios emphasize the importance of obtaining a focused clinical history, performing key neurological assessments (such as neck flexion strength and breath counting), evaluating pulmonary function tests, and identifying when to initiate ventilatory support.²² In a study designed as a simulation-based learning curriculum for status epilepticus, there was an improvement in the performance of PGY-2 residents after completing the curriculum from a median of 44.2% at pretest to 94.2% at posttest.²³ In this curriculum, an emphasis was placed on the following: recognizing the delay in identification and treatment of status epilepticus; evaluating contraindications of certain antiseizure medication (ASM) based on history or laboratory work; giving first-line ASM within 5 minutes of seizure onset; airway and blood pressure assessment; suctioning the patient; use of second-line ASMs after first-line has failed; ordering a head CT and re-evaluating the case with postload ASM level; ordering a stat electroencephalography (EEG); and communicating the decision regarding patient disposition/level of care.²⁴

There is a growing need for well designed simulation education programs targeted at the management of disorders requiring acute neurologic care, including not only stroke and status epilepticus, but also traumatic brain injury, subarachnoid hemorrhage, neuromuscular respiratory failure, flare of multiple sclerosis, acutely elevated intracranial pressure, malignant cerebral infarction, deterioration of Parkinson disease, and brain death evaluation with family counseling.²⁵ This novel approach to teaching provides an opportunity to learn in addition to remediation with repetition of scenario and might be used for maintenance of recertification programs.

PROCEDURAL SKILLs

Perhaps one of the most studied uses for simulation in neurology is in procedural skills. This extends beyond neurology trainees and can include pulmonary critical care fellows, pediatric residents, and internal medicine residents receiving training in neurology-based procedures such as lumbar punctures (LPs). Other examples of neurology procedures and protocols in which simulation has been studied include fundoscopy, brain death evaluation, EEG interpretation in context of status epilepticus, and simulated stroke code responses. Additional procedures that lack research but may benefit from simulation-based training include the use of Doppler ultrasound and botulinum toxin injections practiced on mannequins.

Proficiency in LP procedural skills has been extensively studied by multiple institutions, with trainee levels ranging from medical students to fellows. One study in France enrolled 115 medical students without prior LP experience and randomized them to either a simulation or a control group.²⁶ Those in the simulation group received instruction using a mannequin, and those in the control group received clinical training through hospital rotations. Both groups received an email containing literature-based information on the procedure as well as a self-assessment questionnaire before participating in either educational program. 

The study showed that those students who received simulation training had a success rate of 67% on their first LP on a live patient compared with a success rate of 14% in those with traditional training. Students receiving simulation training required less assistance during the procedure from a supervisor and had higher satisfaction rates and confidence in their procedural skills.²⁶

Another study of 128 medical students at the University of Pittsburgh found that a hybrid LP simulation significantly improved students’ confidence and perceived skill in performing LPs, obtaining informed consent, and electronic order entry. For example, confidence with LP increased from 5.95% presimulation to 90% postsimulation, with 58.24% of students reporting an improvement from minimal or no confidence to average or better (P < .001). Similarly, the proportion of students who felt able to perform LP with minimal or no assistance rose from 0% to 38.57% (P < .001). Confidence and perceived skill in obtaining informed consent and electronic order entry also saw significant gains. Although real-world skill assessments were limited by low survey response rates, preceptor evaluations and follow-up surveys suggested that students who participated in the simulation were more likely to perform these tasks independently or with minimal supervision during clinical rotations.²⁷

Research on simulation training involving nonneurology residents is also encouraging. One study compared the LP skills of traditionally trained neurology residents (PGY-2 to PGY-4) to internal medicine residents (PGY-1) who underwent simulation on a mannequin.²⁸ The internal medicine residents first underwent a pretest on LP performance, watched an educational video, underwent an LP demonstration, and practiced on a mannequin with feedback. The neurology residents completed the checklist-style pretest and performed an LP on a mannequin. Internal medicine residents were found to increase their pretest scores from a mean of 46.3% to 95.7% following training, whereas neurology residents scored a mean of 65.4%. More than half of neurology residents were unable to identify the correct anatomic location or standard cerebrospinal fluid (CSF) tests to be ordered on a routine LP.²⁸

A pediatric resident study in Canada found that following simulation-based training, LP procedural skill improved in 15 of 16 residents tested, and PGY-1 residents showed a reduction in anxiety related to performing the procedure.²⁹

Virtual Reality

An additional tool for simulation is the use of virtual reality (VR) in combination with mannequins. A French study used videos of LPs on actual patients, from equipment set up to final CSF collection and termination of the procedure.³⁰ These videos included a 360-degree view of the procedure. The short video was administered through a VR device (the Oculus Go headset by Microsoft) or by a YouTube video (if VR was not desired).

Participants in the study watched the video then performed an LP on a mannequin. Those who used the VR option had minimal adverse effects (eg, low rates of cybersickness, blurred vision, nausea) and high satisfaction regarding their training environment.³⁰Another VR-based program is the vascular intervention system trainer, which allows clinicians to use endovascular devices and simulate procedures such as thrombectomies. VR simulation is used for trainees and to retrain experienced physicians in performance of high-risk procedures.³¹

Fundoscopic and Ultrasound Simulations

The AR403 eye stimulator device for fundoscopic examinations is a mannequin-based simulation.³² In a single-center, prospective, single-blind study of neurology and pediatric neurology residents, trainees were split into control and intervention groups, with the intervention group receiving simulator training. Both groups received video lectures on fundoscopy techniques. Pre- and postintervention measurements included knowledge, skill, and total scores on the skills assessment. Of the 48 trainees who participated, the intervention group demonstrated significantly higher increases in skills (P = .01) and total (P = .02) scores, although knowledge scores did not improve. The intervention group also reported higher comfort levels, higher confidence, and higher success rates.

Areas that would benefit from simulation training and development include ultrasound training, such as transcranial Doppler evaluation. In a national survey of residents in anesthesia and critical care, trainees reported that simulation was not frequently used in ultrasound training and that bedside teaching was more common. Interestingly, there was a discrepancy between the opinions of residents and program directors. The program directors felt simulation was in fact used (18.2% of program directors reported this vs 5.3% of trainees).³³

A new program, the NewroSim (Gaumard), is a computer-based model of cerebral perfusion that may be a useful tool in this setting. It can simulate blood flow velocities, including pathologic ones, both with a mannequin or without.³⁴

Another potential area for development is the use of mannequins to teach botulinum toxin injections for migraine, dystonia and spasticity in a training environment This is typically led by pharmaceutical representatives who are not necessarily clinicians. Residents and fellows may benefit instead from clinician-led education during their training programs.

Simulation in Patient Communication

Simulation provides a realistic environment for teaching rapid decision-making, leadership, and appropriate management of acutely ill neurologic patients; this includes the communication skills needed in response to neurologic injury.³⁵ Simulation can be particularly useful in situations involving brain death determination, where the communication techniques differ significantly from those used in shared decision-making. Simulation provides a low-stakes setting for clinicians to practice the process of brain death determination and communication, leading to improved confidence and knowledge.³⁶

In the context of acute neurologic emergencies, simulation exercises have been used to investigate the consistency of prognostication across a spectrum of neurology physicians. These exercises revealed that acute neuroprognostication is highly variable and often inaccurate among neurology clinicians, suggesting a potential area for improvement through further simulation training.³⁷

FUTURE DIRECTIONS

Simulation education in neurology can be directed towards learners at all levels, including medical students, residents, fellows, nurses, and medical technologists. In addition, simulation has great value to different disciplines, including emergency medicine, intensive care, and psychiatry. In our view simulation is not being used to full potential in neurology.

Simulation can be used to expose clinicians to rare pathology, play an integral role in competency-based evaluations, and serve as the foundation for simulation-based neurology curriculums, teleneurology simulation training programs, and team training for neurologic emergencies.³⁸Another under-recognized aspect of neurology education is teaching interpersonal communication and professionalism. A survey conducted at a neurology department (20 residents and 73 faculty respondents) asked about residents’ comfort level in performing a number of interpersonal communication and professionalism tasks.³⁸ While none of the residents said they were “very uncomfortable” with these tasks, only 1 resident reported being “very comfortable.” In addition, fewer than 50% noted that they had been directly observed by a faculty member while performing these tasks. The results prompted the facility to develop a simulation curriculum that including observation and feedback from 8 objective structured clinical examinations at a simulation center. A standardized professional simulated the role of a patient, caregiver, medical student, or a faculty member. Residents indicated in postsimulation surveys that it was very useful, and a majority voted for the activity to be repeated for future classes.³⁸

Simulation models may also provide a more objective method to evaluate neurology residents. Accreditation Council for Graduate Medical Education has provided Milestones that are used for assessment of neurology residents. Most of the programs rely on end-of-rotation faculty evaluations. These are subjective evaluations, rely on chance evaluations and may not reflect the exact caliber of a trainee in different clinical situations. Simulation models can serve as alternatives to provide an objective and accurate assessment of resident’s competency in different neurologic scenarios. 

In a study of PGY-4 neurology residents from 3 tertiary care academic medical centers were evaluated using simulation-based assessment. Their skills in identifying and managing status epilepticus were assessed via a simulation-based model and compared with clinical experience. No graduating neurology residents were able to meet or exceed the minimum passing score during the testing. It was suggested that end-of-rotation evaluations are inadequate for assigning level of Milestones.²⁴ To move forward with use of simulation-based assessments, these models need to be trialed more extensively and validated. 

Morris et al developed simulations for assessment in neurocritical care.³⁹ Ten evaluative simulation cases were developed. Researchers reported on 64 trainee participants in 274 evaluative simulation scenarios. The participants were very satisfied with the cases, found them to be very realistic and appropriately difficult. Interrater reliability was acceptable for both checklist action items and global rating scales. The researchers concluded that they were able to demonstrate validity evidence via the 10 simulation cases for assessment in neurologic emergencies.³⁹ It is the authors’ belief that the future of residents’ competency assessment should include more widespread use of similar simulation models. 

Finally, VR and augmented reality (AR) have shown promise in various fields, including neurology. In neurology, these technologies are being explored for applications in rehabilitation, therapy, and medical training. Ongoing research aims to leverage these technologies for improved patient outcomes and medical education. Virtual simulations can recreate neurologic scenarios, allowing learners to interact with 3-dimensional (3D) models of the brain or experience virtual patient cases. AR can enhance traditional learning materials by overlaying digital information onto real-world objects, aiding in the understanding of complex neuroanatomy and medical concepts. These technologies contribute to more engaging and effective neurology education.³⁹In a study of 84 graduate medical students divided into 3 groups, the first group attended a traditional lecture on neuroanatomy, the second group was shown VR-based 3D images, and the third group had a VR-based, interactive and stereoscopic session.⁴⁰ Groups 2 and 3 showed the highest mean scores in evaluations and differed significantly from Group 1 (P < .05). Groups 2 and 3 did not differ significantly from each other. The researchers concluded that VR-based resources for teaching neuroanatomy fostered significantly higher learning when compared to the traditional methods.⁴⁰

Clinical simulation is a technique, not a technology, used to replace or amplify real experiences with guided experiences that evoke or replicate substantial aspects of the real world in a fully interactive fashion.¹ Simulation is widely used in medical education and spans a spectrum of sophistication, from simple reproduction of isolated body parts to high-fidelity human patient simulators that replicate whole body appearance and variable physiological parameters.^2,3

Simulation-based medical education can be a valuable tool for safe health care delivery.⁴Simulation-based education is typically provided via 5 modalities: mannequins, computer-based mannequins, standardized patients, computer-based simulators, and software-based simulations. Simulation technology increases procedural skill by allowing for deliberate practice in a safe environment.⁵ Mastery learning is a stringent form of competency-based education that requires trainees to acquire clinical skill measured against a fixed achievement standard.⁶ In mastery learning, educational practice time varies but results are uniform. This approach improves patient outcomes and is more effective than clinical training alone.^7-9

Advanced simulation models are helpful tools for neurologic education and training, especially for emergency department encounters.¹⁰ In recent years, advanced simulation models have been applied in various fields of medicine, especially emergency medicine and anesthesia.^11-14

Acute neurology

In acute neurologic conditions (eg, stroke, intracerebral hemorrhage, status epilepticus, and neuromuscular respiratory failure) clinical outcomes are highly time dependent; consequently, a reduction in treatment delays can improve patient care. The application of simulation methodology allows trainees to address acute and potentially life-threatening emergencies in a safe, controlled, and reproducible environment. In addition to improving trainees’ knowledge base, simulation also helps to enhance team skills, communication, multidisciplinary collaboration, and leadership. Research has shown that deliberate practice leads to a decrease in clinical errors and improved procedural performance in the operating room.^8,15 These results can be extrapolated to acute neurology settings to improve adherence to set protocols, thus streamlining management in acute settings.

Scenarios can be built to teach skills such as eliciting an appropriate history, establishing inclusion or exclusion criteria for the use of certain medications, evaluating neuroimaging and laboratory studies (while avoiding related common pitfalls), and managing treatment complications. Simulation also provides an opportunity for interprofessional education by training nurses and collaborative staff. It can be used to enhance nontechnical skills (eg, communication, situation awareness, decision making, and leadership) that further contribute to patient safety. 

Simulation can be performed with the help of mannequins such as the SimMan 3G(Laerdal), which can display neurologic symptoms and physiological findings, or live actors who portray a patient by mimicking focal neurologic deficits.^16,17 A briefing familiarizes the trainees with the equipment and explains the simulation process. The documentation and equipment are the same as that which is used in emergency departments or intensive care units. 

Once the simulation is completed, a trainee’s performance is checked against a critical action checklist before a debriefing process during which the scenario is reviewed and learning goals are assessed. Immediate feedback is given to trainees to identify weaknesses and the simulation is repeated if multiple critical action items are missed. (Figure).¹⁷

RESIDENCY TRAINING

Simulation training in stroke is mandatory in some residency programs for neurology postgraduate year (PGY) 2 residents.¹⁸ These simulations are a part of a boot camp for incoming neurology residents after completing an internal medicine internship. The simulation program is not standardized across various training programs. The European Stroke Organization Simulation Committee has published an opinion paper with a consensus of experts about the implementation of simulation techniques in the stroke field.^19,20 Residents participating in these mandatory programs are required to complete certification in the National Institutes of Health Stroke Scale (NIHSS) and the modified Rankin Scale, including a pretest that assesses their knowledge of acute stroke protocols prior to live simulation.¹⁷ A stepwise algorithm that incorporates faculty specialized in the field is used to evaluate and debrief the simulation.

Stroke vignettes are typically selected by the vascular neurology attending physician to cover thrombolytic therapy (indications and contraindications), mechanical thrombectomy, early arterial blood pressure management, anticoagulant reversal protocols, and management of thrombolytic complications (eg, neurologic worsening). Nursing staff is educated on the acute stroke protocol. Computed tomography (CT) and CT angiography scans are retrieved from teaching files. These are provided as live responses along with pertinent laboratory work, vital signs, and electrocardiogram tracings. Trainee performance is based on adherence to a critical action checklist, which includes (but is not limited to) identification of relative and absolute contraindications of thrombolytic treatments, estimation of NIHSS within 5 minutes of arrival, and consideration of candidacy for endovascular intervention.¹⁷

EVIDENCE FOR SIMULATION TRAINING

Simulations for acute ischemic stroke also improve cohesive teamwork to improve the door-to-needle and door-to-puncture time. A retrospective analysis involving first-year neurology residents at a comprehensive stroke center that compared patient cohort data before and after implementation of simulation training found that there was an improvement in door-to-needle time after implementation of stroke simulation training program by nearly 10 minutes.¹⁷ This was likely due to improvement in the comfort of the flow of management across multidisciplinary teams.

Discussing goals of care, communicating poor prognosis or complex decisions with distraught family members or patients requires practice. Simulation programs with video playback help focus on trainee’s body language, avoiding medical jargon and handling ethical dilemmas while adjusting the communication style to the patient’s personality.²⁰ Enhanced communication skills improve patient satisfaction, trust, and adherence to treatments, all of which lead to better outcomes.²¹

Simulation has been effectively used as a training tool for recognizing and managing acute neuromuscular respiratory failure. These scenarios emphasize the importance of obtaining a focused clinical history, performing key neurological assessments (such as neck flexion strength and breath counting), evaluating pulmonary function tests, and identifying when to initiate ventilatory support.²² In a study designed as a simulation-based learning curriculum for status epilepticus, there was an improvement in the performance of PGY-2 residents after completing the curriculum from a median of 44.2% at pretest to 94.2% at posttest.²³ In this curriculum, an emphasis was placed on the following: recognizing the delay in identification and treatment of status epilepticus; evaluating contraindications of certain antiseizure medication (ASM) based on history or laboratory work; giving first-line ASM within 5 minutes of seizure onset; airway and blood pressure assessment; suctioning the patient; use of second-line ASMs after first-line has failed; ordering a head CT and re-evaluating the case with postload ASM level; ordering a stat electroencephalography (EEG); and communicating the decision regarding patient disposition/level of care.²⁴

There is a growing need for well designed simulation education programs targeted at the management of disorders requiring acute neurologic care, including not only stroke and status epilepticus, but also traumatic brain injury, subarachnoid hemorrhage, neuromuscular respiratory failure, flare of multiple sclerosis, acutely elevated intracranial pressure, malignant cerebral infarction, deterioration of Parkinson disease, and brain death evaluation with family counseling.²⁵ This novel approach to teaching provides an opportunity to learn in addition to remediation with repetition of scenario and might be used for maintenance of recertification programs.

PROCEDURAL SKILLs

Perhaps one of the most studied uses for simulation in neurology is in procedural skills. This extends beyond neurology trainees and can include pulmonary critical care fellows, pediatric residents, and internal medicine residents receiving training in neurology-based procedures such as lumbar punctures (LPs). Other examples of neurology procedures and protocols in which simulation has been studied include fundoscopy, brain death evaluation, EEG interpretation in context of status epilepticus, and simulated stroke code responses. Additional procedures that lack research but may benefit from simulation-based training include the use of Doppler ultrasound and botulinum toxin injections practiced on mannequins.

Proficiency in LP procedural skills has been extensively studied by multiple institutions, with trainee levels ranging from medical students to fellows. One study in France enrolled 115 medical students without prior LP experience and randomized them to either a simulation or a control group.²⁶ Those in the simulation group received instruction using a mannequin, and those in the control group received clinical training through hospital rotations. Both groups received an email containing literature-based information on the procedure as well as a self-assessment questionnaire before participating in either educational program. 

The study showed that those students who received simulation training had a success rate of 67% on their first LP on a live patient compared with a success rate of 14% in those with traditional training. Students receiving simulation training required less assistance during the procedure from a supervisor and had higher satisfaction rates and confidence in their procedural skills.²⁶

Another study of 128 medical students at the University of Pittsburgh found that a hybrid LP simulation significantly improved students’ confidence and perceived skill in performing LPs, obtaining informed consent, and electronic order entry. For example, confidence with LP increased from 5.95% presimulation to 90% postsimulation, with 58.24% of students reporting an improvement from minimal or no confidence to average or better (P < .001). Similarly, the proportion of students who felt able to perform LP with minimal or no assistance rose from 0% to 38.57% (P < .001). Confidence and perceived skill in obtaining informed consent and electronic order entry also saw significant gains. Although real-world skill assessments were limited by low survey response rates, preceptor evaluations and follow-up surveys suggested that students who participated in the simulation were more likely to perform these tasks independently or with minimal supervision during clinical rotations.²⁷

Research on simulation training involving nonneurology residents is also encouraging. One study compared the LP skills of traditionally trained neurology residents (PGY-2 to PGY-4) to internal medicine residents (PGY-1) who underwent simulation on a mannequin.²⁸ The internal medicine residents first underwent a pretest on LP performance, watched an educational video, underwent an LP demonstration, and practiced on a mannequin with feedback. The neurology residents completed the checklist-style pretest and performed an LP on a mannequin. Internal medicine residents were found to increase their pretest scores from a mean of 46.3% to 95.7% following training, whereas neurology residents scored a mean of 65.4%. More than half of neurology residents were unable to identify the correct anatomic location or standard cerebrospinal fluid (CSF) tests to be ordered on a routine LP.²⁸

A pediatric resident study in Canada found that following simulation-based training, LP procedural skill improved in 15 of 16 residents tested, and PGY-1 residents showed a reduction in anxiety related to performing the procedure.²⁹

Virtual Reality

An additional tool for simulation is the use of virtual reality (VR) in combination with mannequins. A French study used videos of LPs on actual patients, from equipment set up to final CSF collection and termination of the procedure.³⁰ These videos included a 360-degree view of the procedure. The short video was administered through a VR device (the Oculus Go headset by Microsoft) or by a YouTube video (if VR was not desired).

Participants in the study watched the video then performed an LP on a mannequin. Those who used the VR option had minimal adverse effects (eg, low rates of cybersickness, blurred vision, nausea) and high satisfaction regarding their training environment.³⁰Another VR-based program is the vascular intervention system trainer, which allows clinicians to use endovascular devices and simulate procedures such as thrombectomies. VR simulation is used for trainees and to retrain experienced physicians in performance of high-risk procedures.³¹

Fundoscopic and Ultrasound Simulations

The AR403 eye stimulator device for fundoscopic examinations is a mannequin-based simulation.³² In a single-center, prospective, single-blind study of neurology and pediatric neurology residents, trainees were split into control and intervention groups, with the intervention group receiving simulator training. Both groups received video lectures on fundoscopy techniques. Pre- and postintervention measurements included knowledge, skill, and total scores on the skills assessment. Of the 48 trainees who participated, the intervention group demonstrated significantly higher increases in skills (P = .01) and total (P = .02) scores, although knowledge scores did not improve. The intervention group also reported higher comfort levels, higher confidence, and higher success rates.

Areas that would benefit from simulation training and development include ultrasound training, such as transcranial Doppler evaluation. In a national survey of residents in anesthesia and critical care, trainees reported that simulation was not frequently used in ultrasound training and that bedside teaching was more common. Interestingly, there was a discrepancy between the opinions of residents and program directors. The program directors felt simulation was in fact used (18.2% of program directors reported this vs 5.3% of trainees).³³

A new program, the NewroSim (Gaumard), is a computer-based model of cerebral perfusion that may be a useful tool in this setting. It can simulate blood flow velocities, including pathologic ones, both with a mannequin or without.³⁴

Another potential area for development is the use of mannequins to teach botulinum toxin injections for migraine, dystonia and spasticity in a training environment This is typically led by pharmaceutical representatives who are not necessarily clinicians. Residents and fellows may benefit instead from clinician-led education during their training programs.

Simulation in Patient Communication

Simulation provides a realistic environment for teaching rapid decision-making, leadership, and appropriate management of acutely ill neurologic patients; this includes the communication skills needed in response to neurologic injury.³⁵ Simulation can be particularly useful in situations involving brain death determination, where the communication techniques differ significantly from those used in shared decision-making. Simulation provides a low-stakes setting for clinicians to practice the process of brain death determination and communication, leading to improved confidence and knowledge.³⁶

In the context of acute neurologic emergencies, simulation exercises have been used to investigate the consistency of prognostication across a spectrum of neurology physicians. These exercises revealed that acute neuroprognostication is highly variable and often inaccurate among neurology clinicians, suggesting a potential area for improvement through further simulation training.³⁷

FUTURE DIRECTIONS

Simulation education in neurology can be directed towards learners at all levels, including medical students, residents, fellows, nurses, and medical technologists. In addition, simulation has great value to different disciplines, including emergency medicine, intensive care, and psychiatry. In our view simulation is not being used to full potential in neurology.

Simulation can be used to expose clinicians to rare pathology, play an integral role in competency-based evaluations, and serve as the foundation for simulation-based neurology curriculums, teleneurology simulation training programs, and team training for neurologic emergencies.³⁸Another under-recognized aspect of neurology education is teaching interpersonal communication and professionalism. A survey conducted at a neurology department (20 residents and 73 faculty respondents) asked about residents’ comfort level in performing a number of interpersonal communication and professionalism tasks.³⁸ While none of the residents said they were “very uncomfortable” with these tasks, only 1 resident reported being “very comfortable.” In addition, fewer than 50% noted that they had been directly observed by a faculty member while performing these tasks. The results prompted the facility to develop a simulation curriculum that including observation and feedback from 8 objective structured clinical examinations at a simulation center. A standardized professional simulated the role of a patient, caregiver, medical student, or a faculty member. Residents indicated in postsimulation surveys that it was very useful, and a majority voted for the activity to be repeated for future classes.³⁸

Simulation models may also provide a more objective method to evaluate neurology residents. Accreditation Council for Graduate Medical Education has provided Milestones that are used for assessment of neurology residents. Most of the programs rely on end-of-rotation faculty evaluations. These are subjective evaluations, rely on chance evaluations and may not reflect the exact caliber of a trainee in different clinical situations. Simulation models can serve as alternatives to provide an objective and accurate assessment of resident’s competency in different neurologic scenarios. 

In a study of PGY-4 neurology residents from 3 tertiary care academic medical centers were evaluated using simulation-based assessment. Their skills in identifying and managing status epilepticus were assessed via a simulation-based model and compared with clinical experience. No graduating neurology residents were able to meet or exceed the minimum passing score during the testing. It was suggested that end-of-rotation evaluations are inadequate for assigning level of Milestones.²⁴ To move forward with use of simulation-based assessments, these models need to be trialed more extensively and validated. 

Morris et al developed simulations for assessment in neurocritical care.³⁹ Ten evaluative simulation cases were developed. Researchers reported on 64 trainee participants in 274 evaluative simulation scenarios. The participants were very satisfied with the cases, found them to be very realistic and appropriately difficult. Interrater reliability was acceptable for both checklist action items and global rating scales. The researchers concluded that they were able to demonstrate validity evidence via the 10 simulation cases for assessment in neurologic emergencies.³⁹ It is the authors’ belief that the future of residents’ competency assessment should include more widespread use of similar simulation models. 

Finally, VR and augmented reality (AR) have shown promise in various fields, including neurology. In neurology, these technologies are being explored for applications in rehabilitation, therapy, and medical training. Ongoing research aims to leverage these technologies for improved patient outcomes and medical education. Virtual simulations can recreate neurologic scenarios, allowing learners to interact with 3-dimensional (3D) models of the brain or experience virtual patient cases. AR can enhance traditional learning materials by overlaying digital information onto real-world objects, aiding in the understanding of complex neuroanatomy and medical concepts. These technologies contribute to more engaging and effective neurology education.³⁹In a study of 84 graduate medical students divided into 3 groups, the first group attended a traditional lecture on neuroanatomy, the second group was shown VR-based 3D images, and the third group had a VR-based, interactive and stereoscopic session.⁴⁰ Groups 2 and 3 showed the highest mean scores in evaluations and differed significantly from Group 1 (P < .05). Groups 2 and 3 did not differ significantly from each other. The researchers concluded that VR-based resources for teaching neuroanatomy fostered significantly higher learning when compared to the traditional methods.⁴⁰

Are you seeing any increase or trends in cutaneous adverse effects related to the use of GLP-1 agonists in your practice?

DR. SHIELDS: The use of GLP-1 agonists is increasing substantially across numerous populations. Patients are using these medications not only for weight management and diabetes control but also for blood pressure modulation and cardiovascular risk reduction. The market size is expected to grow at a rate of about 6% until 2027. While severe cutaneous adverse effects still are considered relatively rare with GLP-1 agonist use, mild adverse effects are quite common. Dermatologists should be familiar with these effects and how to manage them. Rare but serious cutaneous reactions include morbilliform drug eruptions, dermal hypersensitivity reactions, panniculitis, and bullous pemphigoid. It is thought that some GLP-1 agonists may cause more skin reactions than others; for example, exenatide extended-release has been associated with cutaneous adverse events more frequently than other GLP-1 agonists in a recent comprehensive literature review.

Do you see a role for dermatologists in monitoring or managing the downstream dermatologic effects of GLP-1 agonists over the next few years?

DR. SHIELDS: Absolutely. When patients develop a drug eruption, bullous pemphigoid, or eosinophilic panniculitis, dermatologists are going to be the ones to diagnose and manage therapy. Awareness of these adverse effects is crucial to timely and thoughtful discussions surrounding medication discontinuation vs a “treat through” approach.

Do you recommend coordinating with endocrinologists or obesity medicine specialists when managing shared patients on GLP-1s (particularly if skin concerns arise)?

DR. SHIELDS: Yes. This is crucial to patient success. Co-management can provide clarity around the indication for therapy and allow for a thoughtful risk-benefit discussion with the patient, primary care physician, endocrinologist, cardiologist, etc. In my practice, I have found that many patients do not want to stop therapy even when they develop cutaneous adverse effects. There are options to transition therapy or treat through in some cases, but having a comprehensive monitoring and therapy plan is critical.

Have you encountered cases in which rapid weight loss from GLP-1s worsened conditions such as loose skin, cellulite, or facial lipoatrophy, leading to new aesthetic concerns? How would you recommend counseling and/or treating affected patients?

DR. SHIELDS: Accelerated facial aging is a noticeable adverse effect in patients who undergo treatment with GLP-1 agonists, especially when used off-label for weight loss. Localized loss of facial fat can result in altered facial proportions and excess skin. There are multiple additional mechanisms that may underlie accelerated facial aging in patients on GLP-1s, and really we are just beginning to scratch the surface of why and how this happens. Understanding these mechanisms will open the door to downstream preventive and therapeutic options. If patients experience new aesthetic concerns, I currently work with them to adjust their medication to slow weight loss, recommend improved nutrition and hydration, encourage exercise and weight training to maintain muscle mass, and engage my cosmetic dermatology colleagues to discuss procedures such as dermal fillers.

All patients starting GLP-1 agonists should be thoroughly counseled on risks and adverse effects of their medication. These are well reported and should be considered carefully. Starting with lower medication dosing in conjunction with slow escalation and careful monitoring can be helpful in combatting these adverse effects.

Are you seeing any increase or trends in cutaneous adverse effects related to the use of GLP-1 agonists in your practice?

DR. SHIELDS: The use of GLP-1 agonists is increasing substantially across numerous populations. Patients are using these medications not only for weight management and diabetes control but also for blood pressure modulation and cardiovascular risk reduction. The market size is expected to grow at a rate of about 6% until 2027. While severe cutaneous adverse effects still are considered relatively rare with GLP-1 agonist use, mild adverse effects are quite common. Dermatologists should be familiar with these effects and how to manage them. Rare but serious cutaneous reactions include morbilliform drug eruptions, dermal hypersensitivity reactions, panniculitis, and bullous pemphigoid. It is thought that some GLP-1 agonists may cause more skin reactions than others; for example, exenatide extended-release has been associated with cutaneous adverse events more frequently than other GLP-1 agonists in a recent comprehensive literature review.

Do you see a role for dermatologists in monitoring or managing the downstream dermatologic effects of GLP-1 agonists over the next few years?

DR. SHIELDS: Absolutely. When patients develop a drug eruption, bullous pemphigoid, or eosinophilic panniculitis, dermatologists are going to be the ones to diagnose and manage therapy. Awareness of these adverse effects is crucial to timely and thoughtful discussions surrounding medication discontinuation vs a “treat through” approach.

Do you recommend coordinating with endocrinologists or obesity medicine specialists when managing shared patients on GLP-1s (particularly if skin concerns arise)?

DR. SHIELDS: Yes. This is crucial to patient success. Co-management can provide clarity around the indication for therapy and allow for a thoughtful risk-benefit discussion with the patient, primary care physician, endocrinologist, cardiologist, etc. In my practice, I have found that many patients do not want to stop therapy even when they develop cutaneous adverse effects. There are options to transition therapy or treat through in some cases, but having a comprehensive monitoring and therapy plan is critical.

Have you encountered cases in which rapid weight loss from GLP-1s worsened conditions such as loose skin, cellulite, or facial lipoatrophy, leading to new aesthetic concerns? How would you recommend counseling and/or treating affected patients?

DR. SHIELDS: Accelerated facial aging is a noticeable adverse effect in patients who undergo treatment with GLP-1 agonists, especially when used off-label for weight loss. Localized loss of facial fat can result in altered facial proportions and excess skin. There are multiple additional mechanisms that may underlie accelerated facial aging in patients on GLP-1s, and really we are just beginning to scratch the surface of why and how this happens. Understanding these mechanisms will open the door to downstream preventive and therapeutic options. If patients experience new aesthetic concerns, I currently work with them to adjust their medication to slow weight loss, recommend improved nutrition and hydration, encourage exercise and weight training to maintain muscle mass, and engage my cosmetic dermatology colleagues to discuss procedures such as dermal fillers.

All patients starting GLP-1 agonists should be thoroughly counseled on risks and adverse effects of their medication. These are well reported and should be considered carefully. Starting with lower medication dosing in conjunction with slow escalation and careful monitoring can be helpful in combatting these adverse effects.

Are you seeing any increase or trends in cutaneous adverse effects related to the use of GLP-1 agonists in your practice?

DR. SHIELDS: The use of GLP-1 agonists is increasing substantially across numerous populations. Patients are using these medications not only for weight management and diabetes control but also for blood pressure modulation and cardiovascular risk reduction. The market size is expected to grow at a rate of about 6% until 2027. While severe cutaneous adverse effects still are considered relatively rare with GLP-1 agonist use, mild adverse effects are quite common. Dermatologists should be familiar with these effects and how to manage them. Rare but serious cutaneous reactions include morbilliform drug eruptions, dermal hypersensitivity reactions, panniculitis, and bullous pemphigoid. It is thought that some GLP-1 agonists may cause more skin reactions than others; for example, exenatide extended-release has been associated with cutaneous adverse events more frequently than other GLP-1 agonists in a recent comprehensive literature review.

Do you see a role for dermatologists in monitoring or managing the downstream dermatologic effects of GLP-1 agonists over the next few years?

DR. SHIELDS: Absolutely. When patients develop a drug eruption, bullous pemphigoid, or eosinophilic panniculitis, dermatologists are going to be the ones to diagnose and manage therapy. Awareness of these adverse effects is crucial to timely and thoughtful discussions surrounding medication discontinuation vs a “treat through” approach.

Do you recommend coordinating with endocrinologists or obesity medicine specialists when managing shared patients on GLP-1s (particularly if skin concerns arise)?

DR. SHIELDS: Yes. This is crucial to patient success. Co-management can provide clarity around the indication for therapy and allow for a thoughtful risk-benefit discussion with the patient, primary care physician, endocrinologist, cardiologist, etc. In my practice, I have found that many patients do not want to stop therapy even when they develop cutaneous adverse effects. There are options to transition therapy or treat through in some cases, but having a comprehensive monitoring and therapy plan is critical.

Have you encountered cases in which rapid weight loss from GLP-1s worsened conditions such as loose skin, cellulite, or facial lipoatrophy, leading to new aesthetic concerns? How would you recommend counseling and/or treating affected patients?

DR. SHIELDS: Accelerated facial aging is a noticeable adverse effect in patients who undergo treatment with GLP-1 agonists, especially when used off-label for weight loss. Localized loss of facial fat can result in altered facial proportions and excess skin. There are multiple additional mechanisms that may underlie accelerated facial aging in patients on GLP-1s, and really we are just beginning to scratch the surface of why and how this happens. Understanding these mechanisms will open the door to downstream preventive and therapeutic options. If patients experience new aesthetic concerns, I currently work with them to adjust their medication to slow weight loss, recommend improved nutrition and hydration, encourage exercise and weight training to maintain muscle mass, and engage my cosmetic dermatology colleagues to discuss procedures such as dermal fillers.

All patients starting GLP-1 agonists should be thoroughly counseled on risks and adverse effects of their medication. These are well reported and should be considered carefully. Starting with lower medication dosing in conjunction with slow escalation and careful monitoring can be helpful in combatting these adverse effects.

Use of artificial intelligence (AI) in dermatology has increased over the past decade, likely driven by advances in deep learning algorithms, computing hardware, and machine learning.¹ Studies comparing the performance of AI algorithms to dermatologists in classifying skin disorders have shown conflicting results.^2,3 In this study, we aimed to analyze AI tools used for diagnosing and classifying skin disease and evaluate the role of dermatologists in the creation of AI technology. We also investigated the number of clinical images used in datasets to train AI programs and compared tools that were created with dermatologist input to those created without dermatologist/clinician involvement.

Methods

A search of PubMed articles indexed for MEDLINE using the terms machine learning, artificial intelligence, and dermatology was conducted on September 18, 2022. Articles were included if they described full-length trials; used machine learning for diagnosis of or screening for dermatologic conditions; and used dermoscopic or gross image datasets of the skin, hair, or nails. Articles were categorized into 4 groups based on the conditions covered: chronic wounds, inflammatory skin diseases, mixed conditions, and pigmented skin lesions. Algorithms were sorted into 4 categories: convolutional/convoluted neural network, deep learning model/deep neural network, AI/artificial neural network, and other. Details regarding Fitzpatrick skin type and skin of color (SoC) inclusion in the articles or AI algorithm datasets were recorded. Univariate and multivariate analyses were performed using Microsoft Excel and SAS Studio 3.8. Sensitivity and specificity were calculated for all included AI technology. Sensitivity, specificity, and the number of clinical images were compared among the included articles using analysis of variance and t tests (α=0.05; P<.05 indicated statistical significance).

Results

Our search yielded 1016 articles, 58 of which met the inclusion criteria. Overall, 25.9% (15/58) of the articles utilized AI to diagnose or classify mixed skin diseases; 22.4% (13/58) for pigmented skin lesions; 19.0% (11/58) for wounds; 17.2% (10/58) for inflammatory skin diseases; and 5.2% (3/58) each for acne, psoriasis, and onychomycosis. Overall, 24.0% (14/58) of articles provided information about Fitzpatrick skin type, and 58.7% (34/58) included clinical images depicting SoC. Furthermore, we found that only 20.7% (12/58) of articles on deep learning models included descriptions of patient ethnicity or race in at least 1 dataset, and only 10.3% (6/58) of studies included any information about skin tone in the dataset. Studies with a dermatologist as the last author (most likely to be supervising the project) were more likely to include clinical images depicting SoC than those without (82.6% [19/23] and 16.7% [3/18], respectively [P=.0411]).

The mean (SD) number of clinical images in the study articles was 28,422 (84,050). Thirty-seven (63.8%) of the study articles included gross images, 17 (29.3%) used dermoscopic images, and 4 (6.9%) used both. Twenty-seven (46.6%) articles used convolutional/convoluted neural networks, 15 (25.9%) used deep learning model/deep neural networks, 8 (13.8%) used other algorithms, 6 (10.3%) used AI/artificial neural network, and 2 (3.4%) used fuzzy algorithms. Most studies were conducted in China (29.3% [17/58]), Germany (12.1% [7/58]), India (10.3% [6/58]), multiple nations (10.3% [6/58]), and the United States (10.3% [6/58]). Overall, 82.8% (48/58) of articles included at least 1 dermatologist coauthor. Sensitivity of the AI models was 0.85, and specificity was 0.85. The average percentage of images in the dataset correctly identified by a physician was 76.87% vs 81.62% of images correctly identified by AI. Average agreement between AI and physician assessment was 77.98%, defined as AI and physician both having the same diagnosis. 

Articles authored by dermatologists contained more clinical images than those without dermatologists in key authorship roles (P<.0001)(eTable). Psoriasis-related algorithms had the fewest (mean [SD]: 3173 [4203]), and pigmented skin lesions had the most clinical images (mean [SD]: 53,19l [155,579]).

Comment

Our results indicated that AI studies with dermatologist authors had significantly more images in their datasets (ie, the set of clinical images of skin lesions used to train AI algorithms in diagnosing or classifying lesions) than those with nondermatologist authors (P<.0001)(eTable). Similarly, in a study of AI technology for skin cancer diagnosis, AI studies with dermatologist authors (ie, included in the development of the AI algorithm) had more images than studies without dermatologist authors.¹ Deep learning textbooks have suggested that 5000 clinical images or training input per output category are needed to produce acceptable algorithm performance, and more than 10 million are needed to produce results superior to human performance.^4-10 Despite advances in AI for dermatologic image analysis, the creation of these models often has been directed by nondermatologists¹; therefore, dermatologist involvement in AI development is necessary to facilitate collection of larger image datasets and optimal performance for image diagnosis/classification tasks.

We found that 20.7% of articles on deep learning models included descriptions of patient ethnicity or race, and only 10.3% of studies included any information about skin tone in the dataset. Furthermore, American investigators primarily trained models using clinical images of patients with lighter skin tones, whereas Chinese investigators exclusively included images depicting darker skin tones. Similarly, in a study of 52 cutaneous imaging deep learning articles, only 17.3% (9/52) reported race and/or Fitzpatrick skin type, and only 7.7% (4/52) of articles included both.^2,6,8 Therefore, dermatologists are needed to contribute images representing diverse populations and collaborate in AI research studies, as their involvement is necessary to ensure the accuracy of AI models in classifying lesions or diagnosing skin lesions across all skin types.

Our search was limited to PubMed, and real-world applications could not be evaluated.

Conclusion

In summary, we found that AI studies with dermatologist authors used larger numbers of clinical images in their datasets and more images representing diverse skin types than studies without. Therefore, we advocate for greater involvement of dermatologists in AI research, which might result in better patient outcomes by improving diagnostic accuracy.

Use of artificial intelligence (AI) in dermatology has increased over the past decade, likely driven by advances in deep learning algorithms, computing hardware, and machine learning.¹ Studies comparing the performance of AI algorithms to dermatologists in classifying skin disorders have shown conflicting results.^2,3 In this study, we aimed to analyze AI tools used for diagnosing and classifying skin disease and evaluate the role of dermatologists in the creation of AI technology. We also investigated the number of clinical images used in datasets to train AI programs and compared tools that were created with dermatologist input to those created without dermatologist/clinician involvement.

Methods

A search of PubMed articles indexed for MEDLINE using the terms machine learning, artificial intelligence, and dermatology was conducted on September 18, 2022. Articles were included if they described full-length trials; used machine learning for diagnosis of or screening for dermatologic conditions; and used dermoscopic or gross image datasets of the skin, hair, or nails. Articles were categorized into 4 groups based on the conditions covered: chronic wounds, inflammatory skin diseases, mixed conditions, and pigmented skin lesions. Algorithms were sorted into 4 categories: convolutional/convoluted neural network, deep learning model/deep neural network, AI/artificial neural network, and other. Details regarding Fitzpatrick skin type and skin of color (SoC) inclusion in the articles or AI algorithm datasets were recorded. Univariate and multivariate analyses were performed using Microsoft Excel and SAS Studio 3.8. Sensitivity and specificity were calculated for all included AI technology. Sensitivity, specificity, and the number of clinical images were compared among the included articles using analysis of variance and t tests (α=0.05; P<.05 indicated statistical significance).

Results

Our search yielded 1016 articles, 58 of which met the inclusion criteria. Overall, 25.9% (15/58) of the articles utilized AI to diagnose or classify mixed skin diseases; 22.4% (13/58) for pigmented skin lesions; 19.0% (11/58) for wounds; 17.2% (10/58) for inflammatory skin diseases; and 5.2% (3/58) each for acne, psoriasis, and onychomycosis. Overall, 24.0% (14/58) of articles provided information about Fitzpatrick skin type, and 58.7% (34/58) included clinical images depicting SoC. Furthermore, we found that only 20.7% (12/58) of articles on deep learning models included descriptions of patient ethnicity or race in at least 1 dataset, and only 10.3% (6/58) of studies included any information about skin tone in the dataset. Studies with a dermatologist as the last author (most likely to be supervising the project) were more likely to include clinical images depicting SoC than those without (82.6% [19/23] and 16.7% [3/18], respectively [P=.0411]).

The mean (SD) number of clinical images in the study articles was 28,422 (84,050). Thirty-seven (63.8%) of the study articles included gross images, 17 (29.3%) used dermoscopic images, and 4 (6.9%) used both. Twenty-seven (46.6%) articles used convolutional/convoluted neural networks, 15 (25.9%) used deep learning model/deep neural networks, 8 (13.8%) used other algorithms, 6 (10.3%) used AI/artificial neural network, and 2 (3.4%) used fuzzy algorithms. Most studies were conducted in China (29.3% [17/58]), Germany (12.1% [7/58]), India (10.3% [6/58]), multiple nations (10.3% [6/58]), and the United States (10.3% [6/58]). Overall, 82.8% (48/58) of articles included at least 1 dermatologist coauthor. Sensitivity of the AI models was 0.85, and specificity was 0.85. The average percentage of images in the dataset correctly identified by a physician was 76.87% vs 81.62% of images correctly identified by AI. Average agreement between AI and physician assessment was 77.98%, defined as AI and physician both having the same diagnosis. 

Articles authored by dermatologists contained more clinical images than those without dermatologists in key authorship roles (P<.0001)(eTable). Psoriasis-related algorithms had the fewest (mean [SD]: 3173 [4203]), and pigmented skin lesions had the most clinical images (mean [SD]: 53,19l [155,579]).

Comment

Our results indicated that AI studies with dermatologist authors had significantly more images in their datasets (ie, the set of clinical images of skin lesions used to train AI algorithms in diagnosing or classifying lesions) than those with nondermatologist authors (P<.0001)(eTable). Similarly, in a study of AI technology for skin cancer diagnosis, AI studies with dermatologist authors (ie, included in the development of the AI algorithm) had more images than studies without dermatologist authors.¹ Deep learning textbooks have suggested that 5000 clinical images or training input per output category are needed to produce acceptable algorithm performance, and more than 10 million are needed to produce results superior to human performance.^4-10 Despite advances in AI for dermatologic image analysis, the creation of these models often has been directed by nondermatologists¹; therefore, dermatologist involvement in AI development is necessary to facilitate collection of larger image datasets and optimal performance for image diagnosis/classification tasks.

We found that 20.7% of articles on deep learning models included descriptions of patient ethnicity or race, and only 10.3% of studies included any information about skin tone in the dataset. Furthermore, American investigators primarily trained models using clinical images of patients with lighter skin tones, whereas Chinese investigators exclusively included images depicting darker skin tones. Similarly, in a study of 52 cutaneous imaging deep learning articles, only 17.3% (9/52) reported race and/or Fitzpatrick skin type, and only 7.7% (4/52) of articles included both.^2,6,8 Therefore, dermatologists are needed to contribute images representing diverse populations and collaborate in AI research studies, as their involvement is necessary to ensure the accuracy of AI models in classifying lesions or diagnosing skin lesions across all skin types.

Our search was limited to PubMed, and real-world applications could not be evaluated.

Conclusion

In summary, we found that AI studies with dermatologist authors used larger numbers of clinical images in their datasets and more images representing diverse skin types than studies without. Therefore, we advocate for greater involvement of dermatologists in AI research, which might result in better patient outcomes by improving diagnostic accuracy.

Use of artificial intelligence (AI) in dermatology has increased over the past decade, likely driven by advances in deep learning algorithms, computing hardware, and machine learning.¹ Studies comparing the performance of AI algorithms to dermatologists in classifying skin disorders have shown conflicting results.^2,3 In this study, we aimed to analyze AI tools used for diagnosing and classifying skin disease and evaluate the role of dermatologists in the creation of AI technology. We also investigated the number of clinical images used in datasets to train AI programs and compared tools that were created with dermatologist input to those created without dermatologist/clinician involvement.

Methods

A search of PubMed articles indexed for MEDLINE using the terms machine learning, artificial intelligence, and dermatology was conducted on September 18, 2022. Articles were included if they described full-length trials; used machine learning for diagnosis of or screening for dermatologic conditions; and used dermoscopic or gross image datasets of the skin, hair, or nails. Articles were categorized into 4 groups based on the conditions covered: chronic wounds, inflammatory skin diseases, mixed conditions, and pigmented skin lesions. Algorithms were sorted into 4 categories: convolutional/convoluted neural network, deep learning model/deep neural network, AI/artificial neural network, and other. Details regarding Fitzpatrick skin type and skin of color (SoC) inclusion in the articles or AI algorithm datasets were recorded. Univariate and multivariate analyses were performed using Microsoft Excel and SAS Studio 3.8. Sensitivity and specificity were calculated for all included AI technology. Sensitivity, specificity, and the number of clinical images were compared among the included articles using analysis of variance and t tests (α=0.05; P<.05 indicated statistical significance).

Results

Our search yielded 1016 articles, 58 of which met the inclusion criteria. Overall, 25.9% (15/58) of the articles utilized AI to diagnose or classify mixed skin diseases; 22.4% (13/58) for pigmented skin lesions; 19.0% (11/58) for wounds; 17.2% (10/58) for inflammatory skin diseases; and 5.2% (3/58) each for acne, psoriasis, and onychomycosis. Overall, 24.0% (14/58) of articles provided information about Fitzpatrick skin type, and 58.7% (34/58) included clinical images depicting SoC. Furthermore, we found that only 20.7% (12/58) of articles on deep learning models included descriptions of patient ethnicity or race in at least 1 dataset, and only 10.3% (6/58) of studies included any information about skin tone in the dataset. Studies with a dermatologist as the last author (most likely to be supervising the project) were more likely to include clinical images depicting SoC than those without (82.6% [19/23] and 16.7% [3/18], respectively [P=.0411]).

The mean (SD) number of clinical images in the study articles was 28,422 (84,050). Thirty-seven (63.8%) of the study articles included gross images, 17 (29.3%) used dermoscopic images, and 4 (6.9%) used both. Twenty-seven (46.6%) articles used convolutional/convoluted neural networks, 15 (25.9%) used deep learning model/deep neural networks, 8 (13.8%) used other algorithms, 6 (10.3%) used AI/artificial neural network, and 2 (3.4%) used fuzzy algorithms. Most studies were conducted in China (29.3% [17/58]), Germany (12.1% [7/58]), India (10.3% [6/58]), multiple nations (10.3% [6/58]), and the United States (10.3% [6/58]). Overall, 82.8% (48/58) of articles included at least 1 dermatologist coauthor. Sensitivity of the AI models was 0.85, and specificity was 0.85. The average percentage of images in the dataset correctly identified by a physician was 76.87% vs 81.62% of images correctly identified by AI. Average agreement between AI and physician assessment was 77.98%, defined as AI and physician both having the same diagnosis. 

Articles authored by dermatologists contained more clinical images than those without dermatologists in key authorship roles (P<.0001)(eTable). Psoriasis-related algorithms had the fewest (mean [SD]: 3173 [4203]), and pigmented skin lesions had the most clinical images (mean [SD]: 53,19l [155,579]).

Comment

Our results indicated that AI studies with dermatologist authors had significantly more images in their datasets (ie, the set of clinical images of skin lesions used to train AI algorithms in diagnosing or classifying lesions) than those with nondermatologist authors (P<.0001)(eTable). Similarly, in a study of AI technology for skin cancer diagnosis, AI studies with dermatologist authors (ie, included in the development of the AI algorithm) had more images than studies without dermatologist authors.¹ Deep learning textbooks have suggested that 5000 clinical images or training input per output category are needed to produce acceptable algorithm performance, and more than 10 million are needed to produce results superior to human performance.^4-10 Despite advances in AI for dermatologic image analysis, the creation of these models often has been directed by nondermatologists¹; therefore, dermatologist involvement in AI development is necessary to facilitate collection of larger image datasets and optimal performance for image diagnosis/classification tasks.

We found that 20.7% of articles on deep learning models included descriptions of patient ethnicity or race, and only 10.3% of studies included any information about skin tone in the dataset. Furthermore, American investigators primarily trained models using clinical images of patients with lighter skin tones, whereas Chinese investigators exclusively included images depicting darker skin tones. Similarly, in a study of 52 cutaneous imaging deep learning articles, only 17.3% (9/52) reported race and/or Fitzpatrick skin type, and only 7.7% (4/52) of articles included both.^2,6,8 Therefore, dermatologists are needed to contribute images representing diverse populations and collaborate in AI research studies, as their involvement is necessary to ensure the accuracy of AI models in classifying lesions or diagnosing skin lesions across all skin types.

Our search was limited to PubMed, and real-world applications could not be evaluated.

Conclusion

In summary, we found that AI studies with dermatologist authors used larger numbers of clinical images in their datasets and more images representing diverse skin types than studies without. Therefore, we advocate for greater involvement of dermatologists in AI research, which might result in better patient outcomes by improving diagnostic accuracy.

Nurse practitioners (NPs) and physician assistants (PAs) often help provide dermatologic care but lack the same mandatory specialized postgraduate training required of board-certified dermatologists (BCDs), which includes at least 3 years of dermatology-focused education in an accredited residency program in addition to an intern year of general medicine, pediatrics, or surgery. Dermatology residency is followed by a certification examination administered by the American Board of Dermatology (ABD) or the American Osteopathic Board of Dermatology, leading to board certification. Some physicians choose to do a fellowship, which typically involves an additional 1 to 2 years of postresidency subspeciality training.

Optional postgraduate dermatology training programs for advanced practice providers (APPs) have been offered by some academic institutions and private practice groups since at least 2003, including Lahey Hospital and Medical Center (Burlington, Massachusetts) as well as the University of Rochester Medical Center (Rochester, New York). Despite a lack of accreditation or standardization, the programs can be beneficial for NPs and PAs to expand their dermatologic knowledge and skills and help bridge the care gap within the specialty. Didactics often are conducted in parallel with the educational activities of the parent institution’s traditional dermatology residency program (eg, lectures, grand rounds). While these programs often are managed by practicing dermatology NPs and PAs, dermatologists also may be involved in their education with didactic instruction, curriculum development, and clinical preceptorship. 

In this cross-sectional study, we identified and evaluated 10 postgraduate dermatology training programs for APPs across the United States. With the growing number of NPs and PAs in the dermatology workforce—both in academic and private practice—it is important for BCDs to be aware of the differences in the dermatology training received in order to ensure safe and effective care is provided through supervisory or collaborative roles (depending on state independent practice laws for APPs and to be aware of the implications these programs may have on the field of dermatology.

Methods

To identify postgraduate dermatology training programs for APPs in the United States, we conducted a cross-sectional study using data obtained via a Google search of various combinations of the following terms: nurse practitioner, NP, physician assistant, PA, advance practice provider, APP, dermatology, postgraduate training, residency, and fellowship. We excluded postgraduate dermatology training programs for APPs that required tuition and did not provide a stipend, as well as programs that lacked the formal structure and credibility needed to qualify as legitimate postgraduate training. Many of the excluded programs operate in a manner that raises ethical concerns, offering pay-to-play opportunities under the guise of education. Information collected on each program included the program name, location, parent institution, program length, class size, curriculum, and any associated salary and benefits.

Results

Ten academic and private practice organizations across the United States that offer postgraduate dermatologic training programs for APPs were identified (eTable). Four (40%) programs were advertised as fellowships. Six (60%) of the programs were offered at academic medical centers, and 4 (40%) were offered by private practices. Most programs were located east of the Mississippi River, and many institutions offered instruction at 1 or more locations within the same state (eFigure). The Advanced Dermatology and Cosmetic Surgery private practice group offered training opportunities in multiple states.

Six programs required APPs to become board-certified NPs or PAs prior to enrolling. Most programs enrolled both NPs and PAs, while some only enrolled NPs (eTable). Only 1 (10%) program required NPs to be board certified as a family NP, while another (10%) recommended that applicants have experience in urgent care, emergency medicine, or trauma medicine. Lahey Hospital & Medical Center required experience as an NP in a general setting for 1 to 2 years prior to applying. No program required prior experience in the field of dermatology.

Program length varied from 6 to 24 months, and cohort size typically was limited to 1 to 2 providers (eTable). Although the exact numbers could not be ascertained, most curricula focused on medical dermatology, including clinical and didactic components, but many offered electives such as cosmetic and procedural dermatology. Two institutions (20%) required independent research. Work typically was limited to 40 hours per week, and most paid a full-time employee salary and provided benefits such as health insurance, retirement, and paid leave (eTable). Kansas Medical Clinic (Topeka, Kansas) required at least 3 years of employment in an underserved community following program completion. The Oasis Dermatology private practice group in Texas required a 1-year teaching commitment after program completion. The Advanced Dermatology and Cosmetic Surgery group offered a full-time position upon program completion.

Comment

There is a large difference in the total number of training and credentialing hours when comparing graduate school training and postgraduate credentialing of medical and osteopathic physicians compared with APPs. A new graduate physician has at least twice as many clinical hours as a PA and 10 times as many clinical hours as an NP prior to starting residency. Physicians also typically complete at least 6 times the number of hours of certification examinations compared to NPs and PAs.¹

Nurse practitioner students typically complete the 500 hours of prelicensure clinical training required for NP school in 2 to 4 years.^2,3 The amount of time required for completion is dependent on the degree and experience of the student upon program entry (eg, bachelor of science in nursing vs master of science in nursing as a terminal degree). Physician assistant students are required to complete 2000 prelicensure clinical hours, and most PA programs are 3 years in duration.⁴ Many NP and PA programs require some degree of clinical experience prior to beginning graduate education.⁵

When comparing prelicensure examinations, questions assessing dermatologic knowledge comprise approximately 6% to 10% of the total questions on the United States Medical Licensing Examination Steps 1 and 2.⁶ The Comprehensive Osteopathic Medical Licensing Examination of the United States Level 1 and Level 2-Cognitive Evaluation both have at least 5% of questions dedicated to dermatology.⁷ Approximately 5% of the questions on the Physician Assistant National Certifying Examination are dedicated to dermatology.⁸ The dermatology content on either of the NP certification examinations is unclear.^2,3 In the states of California, Indiana, and New York, national certification through the American Association of Nurse Practitioners or American Nurses Credentialing Center is not required for NPs to practice in their respective states.⁹

Regarding dermatologic board certification, a new graduate NP may obtain certification from the Dermatology Nurse Practitioner Certification Board with 3000 hours of general dermatology practice that may occur during normal working hours.¹⁰ These hours do not have to occur in one of the previously identified postgraduate APP training programs. The National Board of Dermatology Physician Assistants was founded in 2018 and has since dissolved. The National Board of Dermatology Physician Assistants was not accredited and required at least 3 years of training in dermatology with the same dermatologist in addition to completing a 125-question multiple-choice examination.¹¹ Of note, this examination was opposed by both the ABD and the Society for Dermatology Physician Associates.¹² A PA also may become a Diplomate Fellow with the Society of Dermatology Physician Associates after completion of 64.5 hours of online continuing education modules.⁴ Some PAs may choose to obtain a Certificate of Added Qualifications, which is a voluntary credential that helps document specialty experience and expertise in dermatology or other specialties.

In contrast, a dermatology resident physician requires nearly 11,000 to 13,000 hours of clinical training hours, which last 3 to 4 years following medical school.¹³ This training involves direct patient care under supervision in various settings, including hospitals, outpatient clinics, and surgical procedures. In addition to this clinical experience, dermatology residents must pass a 3-step certification examination process administered by the ABD.¹³ This process includes approximately 20 hours of examinations designed to assess both knowledge and practical skills. For those who wish to further specialize, additional fellowship training in areas such as pediatric dermatology, dermatopathology, or Mohs surgery may follow residency; such fellowships involve an extra 2500 to 3500 hours of training and culminate in another certification examination, further refining a resident’s expertise in a specific dermatologic field. Osteopathic physicians may opt out of the ABD 3-step pathway and obtain board certification through the American Osteopathic Board of Dermatology.¹⁴

Many of the programs we evaluated integrate APP trainees into resident education, allowing participation in equivalent didactic curricula, clinical rotations, and departmental academic activities. The salary and benefits associated with these programs are somewhat like those of resident physicians.^15,16 While most tuition-based programs were excluded from our study due to their lack of credibility and alignment with our study criteria, we identified 2 specific programs that stood out as credible despite requiring students to pay tuition. These programs demonstrated a structured and rigorous curriculum with a clear focus on comprehensive dermatologic training, meeting our standards for inclusion. These programs offer dermatologic training for graduates of NP and PA programs at a cost to the student.^15,16 The program at the Florida Atlantic University, Boca Raton, is largely online,¹⁵ and the program at the University of Miami, Florida, offers no direct clinical contact.¹⁶ These programs illustrate the variety of postgraduate dermatology curricula available nationally in comparison to resident salaries; however, they were not included in our formal analysis because they do not provide structured, in-person clinical training consistent with our inclusion criteria. Neither of these programs would enable participants to qualify for credentialing with the Dermatology Nurse Practitioner Certification Board after completion. While this study identified postgraduate training programs for APPs in dermatology advertised online, it is possible some were omitted or not advertised online.

While many of the postgraduate programs we evaluated provide unique educational opportunities for APPs, it is unknown if graduating providers are equipped to handle the care of patients with complex dermatologic needs. Regardless, the increased utilization of APPs by BCDs has been well documented over the past 2 decades.^17-20 It has been suggested that a higher ratio of APPs to dermatologists can decrease the time it takes for a patient to be seen in a clinic.^21-23 However, investigators have expressed concerns that APPs lack standardized surgical training and clinical hour requirements in the field of dermatology.²⁴ Despite these concerns, Medicare claims data show that APPs are performing advanced surgical and cosmetic procedures at increasing rates.^17,18 Other authors have questioned the cost-effectiveness of APPs, as multiple studies have shown that the number of biopsies needed to diagnose 1 case of skin cancer is higher for midlevel providers than for dermatologists.^25-27

Conclusion

With the anticipated expansion of private equity in dermatology and the growth of our Medicare-eligible population, we are likely to see increased utilization of APPs to address the shortage of BCDs.^28,29 Understanding the prelicensure and postlicensure clinical training requirements, examination hours, and extent of dermatology-focused education among APPs and BCDs can help dermatologists collaborate more effectively and ensure safe, high-quality patient care. Standardizing, improving, and providing high-quality education and promoting lifelong learning in the field of dermatology should be celebrated, and dermatologists are the skin experts best equipped to lead dermatologic education forward.

Nurse practitioners (NPs) and physician assistants (PAs) often help provide dermatologic care but lack the same mandatory specialized postgraduate training required of board-certified dermatologists (BCDs), which includes at least 3 years of dermatology-focused education in an accredited residency program in addition to an intern year of general medicine, pediatrics, or surgery. Dermatology residency is followed by a certification examination administered by the American Board of Dermatology (ABD) or the American Osteopathic Board of Dermatology, leading to board certification. Some physicians choose to do a fellowship, which typically involves an additional 1 to 2 years of postresidency subspeciality training.

Optional postgraduate dermatology training programs for advanced practice providers (APPs) have been offered by some academic institutions and private practice groups since at least 2003, including Lahey Hospital and Medical Center (Burlington, Massachusetts) as well as the University of Rochester Medical Center (Rochester, New York). Despite a lack of accreditation or standardization, the programs can be beneficial for NPs and PAs to expand their dermatologic knowledge and skills and help bridge the care gap within the specialty. Didactics often are conducted in parallel with the educational activities of the parent institution’s traditional dermatology residency program (eg, lectures, grand rounds). While these programs often are managed by practicing dermatology NPs and PAs, dermatologists also may be involved in their education with didactic instruction, curriculum development, and clinical preceptorship. 

In this cross-sectional study, we identified and evaluated 10 postgraduate dermatology training programs for APPs across the United States. With the growing number of NPs and PAs in the dermatology workforce—both in academic and private practice—it is important for BCDs to be aware of the differences in the dermatology training received in order to ensure safe and effective care is provided through supervisory or collaborative roles (depending on state independent practice laws for APPs and to be aware of the implications these programs may have on the field of dermatology.

Methods

To identify postgraduate dermatology training programs for APPs in the United States, we conducted a cross-sectional study using data obtained via a Google search of various combinations of the following terms: nurse practitioner, NP, physician assistant, PA, advance practice provider, APP, dermatology, postgraduate training, residency, and fellowship. We excluded postgraduate dermatology training programs for APPs that required tuition and did not provide a stipend, as well as programs that lacked the formal structure and credibility needed to qualify as legitimate postgraduate training. Many of the excluded programs operate in a manner that raises ethical concerns, offering pay-to-play opportunities under the guise of education. Information collected on each program included the program name, location, parent institution, program length, class size, curriculum, and any associated salary and benefits.

Results

Ten academic and private practice organizations across the United States that offer postgraduate dermatologic training programs for APPs were identified (eTable). Four (40%) programs were advertised as fellowships. Six (60%) of the programs were offered at academic medical centers, and 4 (40%) were offered by private practices. Most programs were located east of the Mississippi River, and many institutions offered instruction at 1 or more locations within the same state (eFigure). The Advanced Dermatology and Cosmetic Surgery private practice group offered training opportunities in multiple states.

Six programs required APPs to become board-certified NPs or PAs prior to enrolling. Most programs enrolled both NPs and PAs, while some only enrolled NPs (eTable). Only 1 (10%) program required NPs to be board certified as a family NP, while another (10%) recommended that applicants have experience in urgent care, emergency medicine, or trauma medicine. Lahey Hospital & Medical Center required experience as an NP in a general setting for 1 to 2 years prior to applying. No program required prior experience in the field of dermatology.

Program length varied from 6 to 24 months, and cohort size typically was limited to 1 to 2 providers (eTable). Although the exact numbers could not be ascertained, most curricula focused on medical dermatology, including clinical and didactic components, but many offered electives such as cosmetic and procedural dermatology. Two institutions (20%) required independent research. Work typically was limited to 40 hours per week, and most paid a full-time employee salary and provided benefits such as health insurance, retirement, and paid leave (eTable). Kansas Medical Clinic (Topeka, Kansas) required at least 3 years of employment in an underserved community following program completion. The Oasis Dermatology private practice group in Texas required a 1-year teaching commitment after program completion. The Advanced Dermatology and Cosmetic Surgery group offered a full-time position upon program completion.

Comment

There is a large difference in the total number of training and credentialing hours when comparing graduate school training and postgraduate credentialing of medical and osteopathic physicians compared with APPs. A new graduate physician has at least twice as many clinical hours as a PA and 10 times as many clinical hours as an NP prior to starting residency. Physicians also typically complete at least 6 times the number of hours of certification examinations compared to NPs and PAs.¹

Nurse practitioner students typically complete the 500 hours of prelicensure clinical training required for NP school in 2 to 4 years.^2,3 The amount of time required for completion is dependent on the degree and experience of the student upon program entry (eg, bachelor of science in nursing vs master of science in nursing as a terminal degree). Physician assistant students are required to complete 2000 prelicensure clinical hours, and most PA programs are 3 years in duration.⁴ Many NP and PA programs require some degree of clinical experience prior to beginning graduate education.⁵

When comparing prelicensure examinations, questions assessing dermatologic knowledge comprise approximately 6% to 10% of the total questions on the United States Medical Licensing Examination Steps 1 and 2.⁶ The Comprehensive Osteopathic Medical Licensing Examination of the United States Level 1 and Level 2-Cognitive Evaluation both have at least 5% of questions dedicated to dermatology.⁷ Approximately 5% of the questions on the Physician Assistant National Certifying Examination are dedicated to dermatology.⁸ The dermatology content on either of the NP certification examinations is unclear.^2,3 In the states of California, Indiana, and New York, national certification through the American Association of Nurse Practitioners or American Nurses Credentialing Center is not required for NPs to practice in their respective states.⁹

Regarding dermatologic board certification, a new graduate NP may obtain certification from the Dermatology Nurse Practitioner Certification Board with 3000 hours of general dermatology practice that may occur during normal working hours.¹⁰ These hours do not have to occur in one of the previously identified postgraduate APP training programs. The National Board of Dermatology Physician Assistants was founded in 2018 and has since dissolved. The National Board of Dermatology Physician Assistants was not accredited and required at least 3 years of training in dermatology with the same dermatologist in addition to completing a 125-question multiple-choice examination.¹¹ Of note, this examination was opposed by both the ABD and the Society for Dermatology Physician Associates.¹² A PA also may become a Diplomate Fellow with the Society of Dermatology Physician Associates after completion of 64.5 hours of online continuing education modules.⁴ Some PAs may choose to obtain a Certificate of Added Qualifications, which is a voluntary credential that helps document specialty experience and expertise in dermatology or other specialties.

In contrast, a dermatology resident physician requires nearly 11,000 to 13,000 hours of clinical training hours, which last 3 to 4 years following medical school.¹³ This training involves direct patient care under supervision in various settings, including hospitals, outpatient clinics, and surgical procedures. In addition to this clinical experience, dermatology residents must pass a 3-step certification examination process administered by the ABD.¹³ This process includes approximately 20 hours of examinations designed to assess both knowledge and practical skills. For those who wish to further specialize, additional fellowship training in areas such as pediatric dermatology, dermatopathology, or Mohs surgery may follow residency; such fellowships involve an extra 2500 to 3500 hours of training and culminate in another certification examination, further refining a resident’s expertise in a specific dermatologic field. Osteopathic physicians may opt out of the ABD 3-step pathway and obtain board certification through the American Osteopathic Board of Dermatology.¹⁴

Many of the programs we evaluated integrate APP trainees into resident education, allowing participation in equivalent didactic curricula, clinical rotations, and departmental academic activities. The salary and benefits associated with these programs are somewhat like those of resident physicians.^15,16 While most tuition-based programs were excluded from our study due to their lack of credibility and alignment with our study criteria, we identified 2 specific programs that stood out as credible despite requiring students to pay tuition. These programs demonstrated a structured and rigorous curriculum with a clear focus on comprehensive dermatologic training, meeting our standards for inclusion. These programs offer dermatologic training for graduates of NP and PA programs at a cost to the student.^15,16 The program at the Florida Atlantic University, Boca Raton, is largely online,¹⁵ and the program at the University of Miami, Florida, offers no direct clinical contact.¹⁶ These programs illustrate the variety of postgraduate dermatology curricula available nationally in comparison to resident salaries; however, they were not included in our formal analysis because they do not provide structured, in-person clinical training consistent with our inclusion criteria. Neither of these programs would enable participants to qualify for credentialing with the Dermatology Nurse Practitioner Certification Board after completion. While this study identified postgraduate training programs for APPs in dermatology advertised online, it is possible some were omitted or not advertised online.

While many of the postgraduate programs we evaluated provide unique educational opportunities for APPs, it is unknown if graduating providers are equipped to handle the care of patients with complex dermatologic needs. Regardless, the increased utilization of APPs by BCDs has been well documented over the past 2 decades.^17-20 It has been suggested that a higher ratio of APPs to dermatologists can decrease the time it takes for a patient to be seen in a clinic.^21-23 However, investigators have expressed concerns that APPs lack standardized surgical training and clinical hour requirements in the field of dermatology.²⁴ Despite these concerns, Medicare claims data show that APPs are performing advanced surgical and cosmetic procedures at increasing rates.^17,18 Other authors have questioned the cost-effectiveness of APPs, as multiple studies have shown that the number of biopsies needed to diagnose 1 case of skin cancer is higher for midlevel providers than for dermatologists.^25-27

Conclusion

With the anticipated expansion of private equity in dermatology and the growth of our Medicare-eligible population, we are likely to see increased utilization of APPs to address the shortage of BCDs.^28,29 Understanding the prelicensure and postlicensure clinical training requirements, examination hours, and extent of dermatology-focused education among APPs and BCDs can help dermatologists collaborate more effectively and ensure safe, high-quality patient care. Standardizing, improving, and providing high-quality education and promoting lifelong learning in the field of dermatology should be celebrated, and dermatologists are the skin experts best equipped to lead dermatologic education forward.

Nurse practitioners (NPs) and physician assistants (PAs) often help provide dermatologic care but lack the same mandatory specialized postgraduate training required of board-certified dermatologists (BCDs), which includes at least 3 years of dermatology-focused education in an accredited residency program in addition to an intern year of general medicine, pediatrics, or surgery. Dermatology residency is followed by a certification examination administered by the American Board of Dermatology (ABD) or the American Osteopathic Board of Dermatology, leading to board certification. Some physicians choose to do a fellowship, which typically involves an additional 1 to 2 years of postresidency subspeciality training.

Optional postgraduate dermatology training programs for advanced practice providers (APPs) have been offered by some academic institutions and private practice groups since at least 2003, including Lahey Hospital and Medical Center (Burlington, Massachusetts) as well as the University of Rochester Medical Center (Rochester, New York). Despite a lack of accreditation or standardization, the programs can be beneficial for NPs and PAs to expand their dermatologic knowledge and skills and help bridge the care gap within the specialty. Didactics often are conducted in parallel with the educational activities of the parent institution’s traditional dermatology residency program (eg, lectures, grand rounds). While these programs often are managed by practicing dermatology NPs and PAs, dermatologists also may be involved in their education with didactic instruction, curriculum development, and clinical preceptorship. 

In this cross-sectional study, we identified and evaluated 10 postgraduate dermatology training programs for APPs across the United States. With the growing number of NPs and PAs in the dermatology workforce—both in academic and private practice—it is important for BCDs to be aware of the differences in the dermatology training received in order to ensure safe and effective care is provided through supervisory or collaborative roles (depending on state independent practice laws for APPs and to be aware of the implications these programs may have on the field of dermatology.

Methods

To identify postgraduate dermatology training programs for APPs in the United States, we conducted a cross-sectional study using data obtained via a Google search of various combinations of the following terms: nurse practitioner, NP, physician assistant, PA, advance practice provider, APP, dermatology, postgraduate training, residency, and fellowship. We excluded postgraduate dermatology training programs for APPs that required tuition and did not provide a stipend, as well as programs that lacked the formal structure and credibility needed to qualify as legitimate postgraduate training. Many of the excluded programs operate in a manner that raises ethical concerns, offering pay-to-play opportunities under the guise of education. Information collected on each program included the program name, location, parent institution, program length, class size, curriculum, and any associated salary and benefits.

Results

Ten academic and private practice organizations across the United States that offer postgraduate dermatologic training programs for APPs were identified (eTable). Four (40%) programs were advertised as fellowships. Six (60%) of the programs were offered at academic medical centers, and 4 (40%) were offered by private practices. Most programs were located east of the Mississippi River, and many institutions offered instruction at 1 or more locations within the same state (eFigure). The Advanced Dermatology and Cosmetic Surgery private practice group offered training opportunities in multiple states.

Six programs required APPs to become board-certified NPs or PAs prior to enrolling. Most programs enrolled both NPs and PAs, while some only enrolled NPs (eTable). Only 1 (10%) program required NPs to be board certified as a family NP, while another (10%) recommended that applicants have experience in urgent care, emergency medicine, or trauma medicine. Lahey Hospital & Medical Center required experience as an NP in a general setting for 1 to 2 years prior to applying. No program required prior experience in the field of dermatology.

Program length varied from 6 to 24 months, and cohort size typically was limited to 1 to 2 providers (eTable). Although the exact numbers could not be ascertained, most curricula focused on medical dermatology, including clinical and didactic components, but many offered electives such as cosmetic and procedural dermatology. Two institutions (20%) required independent research. Work typically was limited to 40 hours per week, and most paid a full-time employee salary and provided benefits such as health insurance, retirement, and paid leave (eTable). Kansas Medical Clinic (Topeka, Kansas) required at least 3 years of employment in an underserved community following program completion. The Oasis Dermatology private practice group in Texas required a 1-year teaching commitment after program completion. The Advanced Dermatology and Cosmetic Surgery group offered a full-time position upon program completion.

Comment

There is a large difference in the total number of training and credentialing hours when comparing graduate school training and postgraduate credentialing of medical and osteopathic physicians compared with APPs. A new graduate physician has at least twice as many clinical hours as a PA and 10 times as many clinical hours as an NP prior to starting residency. Physicians also typically complete at least 6 times the number of hours of certification examinations compared to NPs and PAs.¹

Nurse practitioner students typically complete the 500 hours of prelicensure clinical training required for NP school in 2 to 4 years.^2,3 The amount of time required for completion is dependent on the degree and experience of the student upon program entry (eg, bachelor of science in nursing vs master of science in nursing as a terminal degree). Physician assistant students are required to complete 2000 prelicensure clinical hours, and most PA programs are 3 years in duration.⁴ Many NP and PA programs require some degree of clinical experience prior to beginning graduate education.⁵

When comparing prelicensure examinations, questions assessing dermatologic knowledge comprise approximately 6% to 10% of the total questions on the United States Medical Licensing Examination Steps 1 and 2.⁶ The Comprehensive Osteopathic Medical Licensing Examination of the United States Level 1 and Level 2-Cognitive Evaluation both have at least 5% of questions dedicated to dermatology.⁷ Approximately 5% of the questions on the Physician Assistant National Certifying Examination are dedicated to dermatology.⁸ The dermatology content on either of the NP certification examinations is unclear.^2,3 In the states of California, Indiana, and New York, national certification through the American Association of Nurse Practitioners or American Nurses Credentialing Center is not required for NPs to practice in their respective states.⁹

Regarding dermatologic board certification, a new graduate NP may obtain certification from the Dermatology Nurse Practitioner Certification Board with 3000 hours of general dermatology practice that may occur during normal working hours.¹⁰ These hours do not have to occur in one of the previously identified postgraduate APP training programs. The National Board of Dermatology Physician Assistants was founded in 2018 and has since dissolved. The National Board of Dermatology Physician Assistants was not accredited and required at least 3 years of training in dermatology with the same dermatologist in addition to completing a 125-question multiple-choice examination.¹¹ Of note, this examination was opposed by both the ABD and the Society for Dermatology Physician Associates.¹² A PA also may become a Diplomate Fellow with the Society of Dermatology Physician Associates after completion of 64.5 hours of online continuing education modules.⁴ Some PAs may choose to obtain a Certificate of Added Qualifications, which is a voluntary credential that helps document specialty experience and expertise in dermatology or other specialties.

In contrast, a dermatology resident physician requires nearly 11,000 to 13,000 hours of clinical training hours, which last 3 to 4 years following medical school.¹³ This training involves direct patient care under supervision in various settings, including hospitals, outpatient clinics, and surgical procedures. In addition to this clinical experience, dermatology residents must pass a 3-step certification examination process administered by the ABD.¹³ This process includes approximately 20 hours of examinations designed to assess both knowledge and practical skills. For those who wish to further specialize, additional fellowship training in areas such as pediatric dermatology, dermatopathology, or Mohs surgery may follow residency; such fellowships involve an extra 2500 to 3500 hours of training and culminate in another certification examination, further refining a resident’s expertise in a specific dermatologic field. Osteopathic physicians may opt out of the ABD 3-step pathway and obtain board certification through the American Osteopathic Board of Dermatology.¹⁴

Many of the programs we evaluated integrate APP trainees into resident education, allowing participation in equivalent didactic curricula, clinical rotations, and departmental academic activities. The salary and benefits associated with these programs are somewhat like those of resident physicians.^15,16 While most tuition-based programs were excluded from our study due to their lack of credibility and alignment with our study criteria, we identified 2 specific programs that stood out as credible despite requiring students to pay tuition. These programs demonstrated a structured and rigorous curriculum with a clear focus on comprehensive dermatologic training, meeting our standards for inclusion. These programs offer dermatologic training for graduates of NP and PA programs at a cost to the student.^15,16 The program at the Florida Atlantic University, Boca Raton, is largely online,¹⁵ and the program at the University of Miami, Florida, offers no direct clinical contact.¹⁶ These programs illustrate the variety of postgraduate dermatology curricula available nationally in comparison to resident salaries; however, they were not included in our formal analysis because they do not provide structured, in-person clinical training consistent with our inclusion criteria. Neither of these programs would enable participants to qualify for credentialing with the Dermatology Nurse Practitioner Certification Board after completion. While this study identified postgraduate training programs for APPs in dermatology advertised online, it is possible some were omitted or not advertised online.

While many of the postgraduate programs we evaluated provide unique educational opportunities for APPs, it is unknown if graduating providers are equipped to handle the care of patients with complex dermatologic needs. Regardless, the increased utilization of APPs by BCDs has been well documented over the past 2 decades.^17-20 It has been suggested that a higher ratio of APPs to dermatologists can decrease the time it takes for a patient to be seen in a clinic.^21-23 However, investigators have expressed concerns that APPs lack standardized surgical training and clinical hour requirements in the field of dermatology.²⁴ Despite these concerns, Medicare claims data show that APPs are performing advanced surgical and cosmetic procedures at increasing rates.^17,18 Other authors have questioned the cost-effectiveness of APPs, as multiple studies have shown that the number of biopsies needed to diagnose 1 case of skin cancer is higher for midlevel providers than for dermatologists.^25-27

Conclusion

With the anticipated expansion of private equity in dermatology and the growth of our Medicare-eligible population, we are likely to see increased utilization of APPs to address the shortage of BCDs.^28,29 Understanding the prelicensure and postlicensure clinical training requirements, examination hours, and extent of dermatology-focused education among APPs and BCDs can help dermatologists collaborate more effectively and ensure safe, high-quality patient care. Standardizing, improving, and providing high-quality education and promoting lifelong learning in the field of dermatology should be celebrated, and dermatologists are the skin experts best equipped to lead dermatologic education forward.

Practice Gap

Tattoos have become increasingly prevalent in Western culture, with approximately 1 in 4 Americans having at least 1 tattoo. Individuals invest money, time, and even pain in getting tattoos, many of which hold special personal, family, or religious significance.¹ Various cutaneous pathologies may arise in areas of the skin with tattoos, including malignancies and inflammatory reactions to tattoo pigment, and in these cases, surgical management may be indicated.^2,3

Nonmelanoma skin cancers (NMSCs) such as superficial basal cell carcinomas on broadly sun-damaged areas (eg, trunk, torso), squamous cell carcinomas, reactive keratoacanthomas, and reactive pseudoepitheliomatous squamous hyperplasia diagnosed as squamous cell carcinoma have been reported to occur in or near areas of the skin with tattoos.² Mohs micrographic surgery (MMS) is the standard of care for removing NMSCs, particularly when they manifest in cosmetically sensitive areas.⁴ This treatment option allows for careful guided resection of tumors to minimize the risk for recurrence; it also preserves healthy tissue, which typically results in a smaller radial defect after the procedure is complete. 

Chronic reactions to tattoo pigment may include granulomatous tattoo reactions and pseudolymphomas.³ Treatment options may include immunosuppressives such as intralesional triamcinolone as well as pigment destruction via lasers⁵; however, not all tattoos are responsive to these treatments. Surgical excision is an effective and definitive treatment in this context, as tattoo pigment resides in or above the mid dermis to a depth of approximately 400 μm. Intradermal excision effectively removes the antigenic pigment.⁵

In these clinical scenarios, patients may be hesitant to pursue surgical treatment due to concerns that it may alter tattoo appearance. Many clinicians and surgeons may consider definitive treatment and tattoo preservation to be mutually exclusive, but this is not always the case. We propose a technique that utilizes conservative thickness layers (CTL) to minimize disruption to the appearance of tattoos in MMS for treatment of cutaneous malignancies as well as intradermal excision of tattoo pigment in the setting of chronic inflammatory tattoo reactions.

The Technique

In the appropriate clinical context, CTL can effectively result in defects that heal well by secondary intention and minimize collateral tissue distortion.⁴ Lesions manifesting in or near tattooed skin often are responsive to treatment with CTL; furthermore, CTL may preserve some deeper tattoo pigment, resulting in only partial loss of the tattooed skin.

Conservative thickness layers are performed intradermally, similar to removing traditional layers in MMS. For treatment of NMSCs, a margin is scored around the lesion, and then the blade is passed carefully under the lesion nearly parallel to the skin through an intradermal plane. It is important to avoid entering the subcuticular fat (Figure 1). The tissue then is processed normally in the Mohs laboratory for complete circumferential margin evaluation. If necessary and possible, subsequent layers also can be performed in the intradermal plane. Once total circumferential margin control is obtained, the wound is allowed to granulate and heal by secondary intention. As these processes occur, we have found that wound contraction is less likely with the dermis intact, resulting in less impact on the overall appearance of the tattoo (Figures 1 and 2). For very thin lesions, resultant defects may retain some residual tattoo pigment. The residual scars also may be responsive to tattoo revision, although a period of monitoring for recurrence should be considered if there is concern that revising the tattoo could obscure early recurrent tumors. From our experience, utilizing CTL for NMSCs that arise within or near tattoos results in favorable preservation of the tattoo appearance and high patient satisfaction.

The procedure is performed similarly for removal of allergenic tattoo pigment, with careful excision to the mid dermis. Since the areas affected by the cutaneous reaction may be relatively large, surgical precision is required to maintain a uniform depth to remove the tattoo pigment and preserve the deep dermis (Figure 2). Once removed, the defect can be left to granulate and heal by secondary intention. If the patient wants to have the tattoo revised in the future, it would be prudent to utilize pigment that the patient has responded favorably to. In our experience, this approach is effective and yields high patient satisfaction and minimizes morbidity.

Practice Implications

Tattoos often hold special meaning for patients; therefore, treatment of pathologies arising in or near tattooed skin should emphasize maintaining the appearance of the tattoo while still being effective. Conservative thickness layers in MMS and intradermal excisions for allergic reactions to tattoo pigment are an effective treatment strategy that clinicians may consider.

One shortcoming of using CTL for MMS is the need for subsequent layers to clear the tumor; however, data suggest that first-stage cure rates are extremely high even with CTL for appropriately selected patients, with clearance of nearly 80% of tumors on the first stage. Tumors that may be most responsive to CTL include exophytic NMSCs and those arising in areas with a thicker dermis, including the back, legs, and scalp, although other locations including the face, hands, shins, ankles, and feet also may be well suited for CTL.⁴ Another shortcoming of CTL is that skin cancers arising in tattoos may not be considered appropriate for MMS based on the 2012 Appropriate Use Criteria, which consider factors such as location, type of cancer, size of the lesion, and patient characteristics to determine whether a skin cancer is appropriate for treatment with MMS.⁶ When the Appropriate Use Criteria categorizes a cancer as uncertain or inappropriate for MMS, the clinician must use their clinical judgment to determine whether MMS is the preferred treatment approach.⁷ Given the cosmetic significance of tattoos, location of a skin cancer near a tattoo could be taken into account for skin cancers that might otherwise not meet Appropriate Use Criteria. 

Conservative thickness layers in MMS and intradermal excisions of tattoo pigment are both effective techniques of minimizing disruption of tattoos while effectively treating patients.

Practice Gap

Tattoos have become increasingly prevalent in Western culture, with approximately 1 in 4 Americans having at least 1 tattoo. Individuals invest money, time, and even pain in getting tattoos, many of which hold special personal, family, or religious significance.¹ Various cutaneous pathologies may arise in areas of the skin with tattoos, including malignancies and inflammatory reactions to tattoo pigment, and in these cases, surgical management may be indicated.^2,3

Nonmelanoma skin cancers (NMSCs) such as superficial basal cell carcinomas on broadly sun-damaged areas (eg, trunk, torso), squamous cell carcinomas, reactive keratoacanthomas, and reactive pseudoepitheliomatous squamous hyperplasia diagnosed as squamous cell carcinoma have been reported to occur in or near areas of the skin with tattoos.² Mohs micrographic surgery (MMS) is the standard of care for removing NMSCs, particularly when they manifest in cosmetically sensitive areas.⁴ This treatment option allows for careful guided resection of tumors to minimize the risk for recurrence; it also preserves healthy tissue, which typically results in a smaller radial defect after the procedure is complete. 

Chronic reactions to tattoo pigment may include granulomatous tattoo reactions and pseudolymphomas.³ Treatment options may include immunosuppressives such as intralesional triamcinolone as well as pigment destruction via lasers⁵; however, not all tattoos are responsive to these treatments. Surgical excision is an effective and definitive treatment in this context, as tattoo pigment resides in or above the mid dermis to a depth of approximately 400 μm. Intradermal excision effectively removes the antigenic pigment.⁵

In these clinical scenarios, patients may be hesitant to pursue surgical treatment due to concerns that it may alter tattoo appearance. Many clinicians and surgeons may consider definitive treatment and tattoo preservation to be mutually exclusive, but this is not always the case. We propose a technique that utilizes conservative thickness layers (CTL) to minimize disruption to the appearance of tattoos in MMS for treatment of cutaneous malignancies as well as intradermal excision of tattoo pigment in the setting of chronic inflammatory tattoo reactions.

The Technique

In the appropriate clinical context, CTL can effectively result in defects that heal well by secondary intention and minimize collateral tissue distortion.⁴ Lesions manifesting in or near tattooed skin often are responsive to treatment with CTL; furthermore, CTL may preserve some deeper tattoo pigment, resulting in only partial loss of the tattooed skin.

Conservative thickness layers are performed intradermally, similar to removing traditional layers in MMS. For treatment of NMSCs, a margin is scored around the lesion, and then the blade is passed carefully under the lesion nearly parallel to the skin through an intradermal plane. It is important to avoid entering the subcuticular fat (Figure 1). The tissue then is processed normally in the Mohs laboratory for complete circumferential margin evaluation. If necessary and possible, subsequent layers also can be performed in the intradermal plane. Once total circumferential margin control is obtained, the wound is allowed to granulate and heal by secondary intention. As these processes occur, we have found that wound contraction is less likely with the dermis intact, resulting in less impact on the overall appearance of the tattoo (Figures 1 and 2). For very thin lesions, resultant defects may retain some residual tattoo pigment. The residual scars also may be responsive to tattoo revision, although a period of monitoring for recurrence should be considered if there is concern that revising the tattoo could obscure early recurrent tumors. From our experience, utilizing CTL for NMSCs that arise within or near tattoos results in favorable preservation of the tattoo appearance and high patient satisfaction.

The procedure is performed similarly for removal of allergenic tattoo pigment, with careful excision to the mid dermis. Since the areas affected by the cutaneous reaction may be relatively large, surgical precision is required to maintain a uniform depth to remove the tattoo pigment and preserve the deep dermis (Figure 2). Once removed, the defect can be left to granulate and heal by secondary intention. If the patient wants to have the tattoo revised in the future, it would be prudent to utilize pigment that the patient has responded favorably to. In our experience, this approach is effective and yields high patient satisfaction and minimizes morbidity.

Practice Implications

Tattoos often hold special meaning for patients; therefore, treatment of pathologies arising in or near tattooed skin should emphasize maintaining the appearance of the tattoo while still being effective. Conservative thickness layers in MMS and intradermal excisions for allergic reactions to tattoo pigment are an effective treatment strategy that clinicians may consider.

One shortcoming of using CTL for MMS is the need for subsequent layers to clear the tumor; however, data suggest that first-stage cure rates are extremely high even with CTL for appropriately selected patients, with clearance of nearly 80% of tumors on the first stage. Tumors that may be most responsive to CTL include exophytic NMSCs and those arising in areas with a thicker dermis, including the back, legs, and scalp, although other locations including the face, hands, shins, ankles, and feet also may be well suited for CTL.⁴ Another shortcoming of CTL is that skin cancers arising in tattoos may not be considered appropriate for MMS based on the 2012 Appropriate Use Criteria, which consider factors such as location, type of cancer, size of the lesion, and patient characteristics to determine whether a skin cancer is appropriate for treatment with MMS.⁶ When the Appropriate Use Criteria categorizes a cancer as uncertain or inappropriate for MMS, the clinician must use their clinical judgment to determine whether MMS is the preferred treatment approach.⁷ Given the cosmetic significance of tattoos, location of a skin cancer near a tattoo could be taken into account for skin cancers that might otherwise not meet Appropriate Use Criteria. 

Conservative thickness layers in MMS and intradermal excisions of tattoo pigment are both effective techniques of minimizing disruption of tattoos while effectively treating patients.

Practice Gap

Tattoos have become increasingly prevalent in Western culture, with approximately 1 in 4 Americans having at least 1 tattoo. Individuals invest money, time, and even pain in getting tattoos, many of which hold special personal, family, or religious significance.¹ Various cutaneous pathologies may arise in areas of the skin with tattoos, including malignancies and inflammatory reactions to tattoo pigment, and in these cases, surgical management may be indicated.^2,3

Nonmelanoma skin cancers (NMSCs) such as superficial basal cell carcinomas on broadly sun-damaged areas (eg, trunk, torso), squamous cell carcinomas, reactive keratoacanthomas, and reactive pseudoepitheliomatous squamous hyperplasia diagnosed as squamous cell carcinoma have been reported to occur in or near areas of the skin with tattoos.² Mohs micrographic surgery (MMS) is the standard of care for removing NMSCs, particularly when they manifest in cosmetically sensitive areas.⁴ This treatment option allows for careful guided resection of tumors to minimize the risk for recurrence; it also preserves healthy tissue, which typically results in a smaller radial defect after the procedure is complete. 

Chronic reactions to tattoo pigment may include granulomatous tattoo reactions and pseudolymphomas.³ Treatment options may include immunosuppressives such as intralesional triamcinolone as well as pigment destruction via lasers⁵; however, not all tattoos are responsive to these treatments. Surgical excision is an effective and definitive treatment in this context, as tattoo pigment resides in or above the mid dermis to a depth of approximately 400 μm. Intradermal excision effectively removes the antigenic pigment.⁵

In these clinical scenarios, patients may be hesitant to pursue surgical treatment due to concerns that it may alter tattoo appearance. Many clinicians and surgeons may consider definitive treatment and tattoo preservation to be mutually exclusive, but this is not always the case. We propose a technique that utilizes conservative thickness layers (CTL) to minimize disruption to the appearance of tattoos in MMS for treatment of cutaneous malignancies as well as intradermal excision of tattoo pigment in the setting of chronic inflammatory tattoo reactions.

The Technique

In the appropriate clinical context, CTL can effectively result in defects that heal well by secondary intention and minimize collateral tissue distortion.⁴ Lesions manifesting in or near tattooed skin often are responsive to treatment with CTL; furthermore, CTL may preserve some deeper tattoo pigment, resulting in only partial loss of the tattooed skin.

Conservative thickness layers are performed intradermally, similar to removing traditional layers in MMS. For treatment of NMSCs, a margin is scored around the lesion, and then the blade is passed carefully under the lesion nearly parallel to the skin through an intradermal plane. It is important to avoid entering the subcuticular fat (Figure 1). The tissue then is processed normally in the Mohs laboratory for complete circumferential margin evaluation. If necessary and possible, subsequent layers also can be performed in the intradermal plane. Once total circumferential margin control is obtained, the wound is allowed to granulate and heal by secondary intention. As these processes occur, we have found that wound contraction is less likely with the dermis intact, resulting in less impact on the overall appearance of the tattoo (Figures 1 and 2). For very thin lesions, resultant defects may retain some residual tattoo pigment. The residual scars also may be responsive to tattoo revision, although a period of monitoring for recurrence should be considered if there is concern that revising the tattoo could obscure early recurrent tumors. From our experience, utilizing CTL for NMSCs that arise within or near tattoos results in favorable preservation of the tattoo appearance and high patient satisfaction.

The procedure is performed similarly for removal of allergenic tattoo pigment, with careful excision to the mid dermis. Since the areas affected by the cutaneous reaction may be relatively large, surgical precision is required to maintain a uniform depth to remove the tattoo pigment and preserve the deep dermis (Figure 2). Once removed, the defect can be left to granulate and heal by secondary intention. If the patient wants to have the tattoo revised in the future, it would be prudent to utilize pigment that the patient has responded favorably to. In our experience, this approach is effective and yields high patient satisfaction and minimizes morbidity.

Practice Implications

Tattoos often hold special meaning for patients; therefore, treatment of pathologies arising in or near tattooed skin should emphasize maintaining the appearance of the tattoo while still being effective. Conservative thickness layers in MMS and intradermal excisions for allergic reactions to tattoo pigment are an effective treatment strategy that clinicians may consider.

One shortcoming of using CTL for MMS is the need for subsequent layers to clear the tumor; however, data suggest that first-stage cure rates are extremely high even with CTL for appropriately selected patients, with clearance of nearly 80% of tumors on the first stage. Tumors that may be most responsive to CTL include exophytic NMSCs and those arising in areas with a thicker dermis, including the back, legs, and scalp, although other locations including the face, hands, shins, ankles, and feet also may be well suited for CTL.⁴ Another shortcoming of CTL is that skin cancers arising in tattoos may not be considered appropriate for MMS based on the 2012 Appropriate Use Criteria, which consider factors such as location, type of cancer, size of the lesion, and patient characteristics to determine whether a skin cancer is appropriate for treatment with MMS.⁶ When the Appropriate Use Criteria categorizes a cancer as uncertain or inappropriate for MMS, the clinician must use their clinical judgment to determine whether MMS is the preferred treatment approach.⁷ Given the cosmetic significance of tattoos, location of a skin cancer near a tattoo could be taken into account for skin cancers that might otherwise not meet Appropriate Use Criteria. 

Conservative thickness layers in MMS and intradermal excisions of tattoo pigment are both effective techniques of minimizing disruption of tattoos while effectively treating patients.

The biopsy revealed hyperkeratosis, hypergranulosis, follicular plugging, vacuolar interface dermatitis with apoptotic bodies, dyskeratotic keratinocytes, pigment incontinence, and melanophages. A perivascular, perifollicular, and periadnexal lymphoplasmacytic inflammatory infiltrate was noted in the superficial and deep dermis (Figure). Based on the characteristic clinical morphology, dermoscopic features, and histopathology, a diagnosis of discoid lupus erythematosus (DLE) was established. The patient was started on mometasone cream 0.1% and tacrolimus ointment 0.1% once daily, with strict recommendations for photoprotection. However, he subsequently was lost to follow-up, and treatment response could not be assessed.

Lupus erythematosus is a multisystemic autoimmune disease with a predilection for skin involvement that is characterized by the production of autoantibodies against nuclear antigens. Discoid lupus erythematosus is the predominant form of the disease, mostly affecting middle-aged women (female-to-male ratio, 4.1:1).¹ Discoid lupus erythematosus usually manifests as well-demarcated, erythematous patches or plaques with partially adherent scales that extend into a patulous follicle. On removal, the scales show horny plugs underneath. This classic finding is known as the carpet tack sign.

As the lesions evolve, they expand with hyperpigmentation at the periphery as well as hypopigmentation, atrophy, scarring, and telangiectasias at the center.² In our patient, the history of discharge and crusting of the lesion and the presence of slight central atrophy—all of which could be attributed to chronic application of topical medications such as corticosteroids, which can cause epidermal thinning, maceration, and secondary crust formation—raised clinical suspicion of cutaneous infections (eg, cutaneous leishmaniasis, lupus vulgaris) and squamous cell carcinoma. The presence of slightly raised margins upon clinical examination brought basal cell carcinoma (BCC) into the differential.

Dermoscopic features commonly seen in DLE reflect the pathologic findings. Follicular plugging and perifollicular white halos correspond to follicular hyperkeratosis and perifollicular fibrosis, respectively (eTable). Disease duration has been shown to alter the dermoscopic appearance of DLE with early active disease showing radially arranged arborizing blood vessels between perifollicular white halos along with follicular red dots, whereas lesions of longer duration display structureless white areas secondary to dermal fibrosis.³ Additionally, background erythema due to neoangiogenesis and dermal inflammation suggests that the disease is in its active state.

On dermoscopy, pigmentation structures such as brown dots, brown lines, and grey-brown dots and globules were seen more prominently in our patient with skin of color, making the underlying erythema more subtle than in patients with lighter skin types. Dotted and linear vessels also were seen in our patient, but not as prominently as typically is seen in lighter skin types.⁴

Lupus vulgaris was ruled out in our patient based on the absence of the typical orange to yellowish-orange background with vessels or any histopathologic evidence of epithelioid granulomas.⁵ Cutaneous leishmaniasis is characterized by polymorphic vascularization, erythema, follicular plugs, yellow-orange structureless areas with scales, and crusts on dermoscopy.⁶ Squamous cell carcinoma tends to show white structureless areas, looped vessels, and central keratin.⁷

Superficial BCC also appears as thin plaques or patches bound by a well-circumscribed, slightly raised, irregular margin. However, on dermoscopy, BCC typically exhibits spoke-wheel areas, arborizing vessels, comma vessels, and concentric structures.⁸

The clinical manifestations of crusting, discharge, and a raised border was atypical, probably owing to the long-term unsupervised application of topical medications, which made the initial diagnosis challenging. Therefore, various differential diagnoses were considered. Dermoscopic evaluation coupled with histology was performed, which ultimately confirmed the diagnosis of DLE.

The biopsy revealed hyperkeratosis, hypergranulosis, follicular plugging, vacuolar interface dermatitis with apoptotic bodies, dyskeratotic keratinocytes, pigment incontinence, and melanophages. A perivascular, perifollicular, and periadnexal lymphoplasmacytic inflammatory infiltrate was noted in the superficial and deep dermis (Figure). Based on the characteristic clinical morphology, dermoscopic features, and histopathology, a diagnosis of discoid lupus erythematosus (DLE) was established. The patient was started on mometasone cream 0.1% and tacrolimus ointment 0.1% once daily, with strict recommendations for photoprotection. However, he subsequently was lost to follow-up, and treatment response could not be assessed.

Lupus erythematosus is a multisystemic autoimmune disease with a predilection for skin involvement that is characterized by the production of autoantibodies against nuclear antigens. Discoid lupus erythematosus is the predominant form of the disease, mostly affecting middle-aged women (female-to-male ratio, 4.1:1).¹ Discoid lupus erythematosus usually manifests as well-demarcated, erythematous patches or plaques with partially adherent scales that extend into a patulous follicle. On removal, the scales show horny plugs underneath. This classic finding is known as the carpet tack sign.

As the lesions evolve, they expand with hyperpigmentation at the periphery as well as hypopigmentation, atrophy, scarring, and telangiectasias at the center.² In our patient, the history of discharge and crusting of the lesion and the presence of slight central atrophy—all of which could be attributed to chronic application of topical medications such as corticosteroids, which can cause epidermal thinning, maceration, and secondary crust formation—raised clinical suspicion of cutaneous infections (eg, cutaneous leishmaniasis, lupus vulgaris) and squamous cell carcinoma. The presence of slightly raised margins upon clinical examination brought basal cell carcinoma (BCC) into the differential.

Dermoscopic features commonly seen in DLE reflect the pathologic findings. Follicular plugging and perifollicular white halos correspond to follicular hyperkeratosis and perifollicular fibrosis, respectively (eTable). Disease duration has been shown to alter the dermoscopic appearance of DLE with early active disease showing radially arranged arborizing blood vessels between perifollicular white halos along with follicular red dots, whereas lesions of longer duration display structureless white areas secondary to dermal fibrosis.³ Additionally, background erythema due to neoangiogenesis and dermal inflammation suggests that the disease is in its active state.

On dermoscopy, pigmentation structures such as brown dots, brown lines, and grey-brown dots and globules were seen more prominently in our patient with skin of color, making the underlying erythema more subtle than in patients with lighter skin types. Dotted and linear vessels also were seen in our patient, but not as prominently as typically is seen in lighter skin types.⁴

Lupus vulgaris was ruled out in our patient based on the absence of the typical orange to yellowish-orange background with vessels or any histopathologic evidence of epithelioid granulomas.⁵ Cutaneous leishmaniasis is characterized by polymorphic vascularization, erythema, follicular plugs, yellow-orange structureless areas with scales, and crusts on dermoscopy.⁶ Squamous cell carcinoma tends to show white structureless areas, looped vessels, and central keratin.⁷

Superficial BCC also appears as thin plaques or patches bound by a well-circumscribed, slightly raised, irregular margin. However, on dermoscopy, BCC typically exhibits spoke-wheel areas, arborizing vessels, comma vessels, and concentric structures.⁸

The clinical manifestations of crusting, discharge, and a raised border was atypical, probably owing to the long-term unsupervised application of topical medications, which made the initial diagnosis challenging. Therefore, various differential diagnoses were considered. Dermoscopic evaluation coupled with histology was performed, which ultimately confirmed the diagnosis of DLE.

The biopsy revealed hyperkeratosis, hypergranulosis, follicular plugging, vacuolar interface dermatitis with apoptotic bodies, dyskeratotic keratinocytes, pigment incontinence, and melanophages. A perivascular, perifollicular, and periadnexal lymphoplasmacytic inflammatory infiltrate was noted in the superficial and deep dermis (Figure). Based on the characteristic clinical morphology, dermoscopic features, and histopathology, a diagnosis of discoid lupus erythematosus (DLE) was established. The patient was started on mometasone cream 0.1% and tacrolimus ointment 0.1% once daily, with strict recommendations for photoprotection. However, he subsequently was lost to follow-up, and treatment response could not be assessed.

Lupus erythematosus is a multisystemic autoimmune disease with a predilection for skin involvement that is characterized by the production of autoantibodies against nuclear antigens. Discoid lupus erythematosus is the predominant form of the disease, mostly affecting middle-aged women (female-to-male ratio, 4.1:1).¹ Discoid lupus erythematosus usually manifests as well-demarcated, erythematous patches or plaques with partially adherent scales that extend into a patulous follicle. On removal, the scales show horny plugs underneath. This classic finding is known as the carpet tack sign.

As the lesions evolve, they expand with hyperpigmentation at the periphery as well as hypopigmentation, atrophy, scarring, and telangiectasias at the center.² In our patient, the history of discharge and crusting of the lesion and the presence of slight central atrophy—all of which could be attributed to chronic application of topical medications such as corticosteroids, which can cause epidermal thinning, maceration, and secondary crust formation—raised clinical suspicion of cutaneous infections (eg, cutaneous leishmaniasis, lupus vulgaris) and squamous cell carcinoma. The presence of slightly raised margins upon clinical examination brought basal cell carcinoma (BCC) into the differential.

Dermoscopic features commonly seen in DLE reflect the pathologic findings. Follicular plugging and perifollicular white halos correspond to follicular hyperkeratosis and perifollicular fibrosis, respectively (eTable). Disease duration has been shown to alter the dermoscopic appearance of DLE with early active disease showing radially arranged arborizing blood vessels between perifollicular white halos along with follicular red dots, whereas lesions of longer duration display structureless white areas secondary to dermal fibrosis.³ Additionally, background erythema due to neoangiogenesis and dermal inflammation suggests that the disease is in its active state.

On dermoscopy, pigmentation structures such as brown dots, brown lines, and grey-brown dots and globules were seen more prominently in our patient with skin of color, making the underlying erythema more subtle than in patients with lighter skin types. Dotted and linear vessels also were seen in our patient, but not as prominently as typically is seen in lighter skin types.⁴

Lupus vulgaris was ruled out in our patient based on the absence of the typical orange to yellowish-orange background with vessels or any histopathologic evidence of epithelioid granulomas.⁵ Cutaneous leishmaniasis is characterized by polymorphic vascularization, erythema, follicular plugs, yellow-orange structureless areas with scales, and crusts on dermoscopy.⁶ Squamous cell carcinoma tends to show white structureless areas, looped vessels, and central keratin.⁷

Superficial BCC also appears as thin plaques or patches bound by a well-circumscribed, slightly raised, irregular margin. However, on dermoscopy, BCC typically exhibits spoke-wheel areas, arborizing vessels, comma vessels, and concentric structures.⁸

The clinical manifestations of crusting, discharge, and a raised border was atypical, probably owing to the long-term unsupervised application of topical medications, which made the initial diagnosis challenging. Therefore, various differential diagnoses were considered. Dermoscopic evaluation coupled with histology was performed, which ultimately confirmed the diagnosis of DLE.

Sporotrichosis is an implantation mycosis that classically manifests as a localized skin and subcutaneous fungal infection but may disseminate to other parts of the body.¹ It is caused by several species within the Sporothrix genus² and is associated with varying clinical manifestations, geographic distributions, virulence profiles, and antifungal susceptibility patterns.^3,4 Transmission of the fungus can involve inoculation from wild or domestic animals (eg, cats).^5,6 Occupations such as landscaping and gardening or elements in the environment (eg, soil, plant fragments) also can be sources of exposure.^7,8

Sporotrichosis is recognized by the World Health Organization as a neglected tropical disease that warrants global advocacy to prevent infections and improve patient outcomes.^9,10 It carries substantial stigma and socioeconomic burden.^11,12 Diagnostics, species identification, and antifungal susceptibility testing often are limited, particularly in resource-limited settings.¹³ In this article, we outline steps to diagnose and manage sporotrichosis to improve care for affected patients globally.

Epidemiology

Sporotrichosis occurs worldwide but is most common in tropical and subtropical regions.^14,15 Outbreaks and clusters of sporotrichosis have been observed across North, Central, and South America as well as in southern Africa and Asia. The estimated annual incidence is 40,000 cases worldwide,^16-20 but global case counts likely are underestimated due to limited surveillance data and diagnostic capability.²¹

On the Asian subcontinent, Sporothrix globosa is the predominant causative species of sporotrichosis, typically via contaminated plant material²²; however, at least 1 outbreak has been associated with severe flooding.²³ In Africa, infections are most commonly caused by Sporothrix schenckii sensu stricto through a similar transmission route. Across Central America, S schenckii sensu stricto is the predominant causative species; however, Sporothrix brasiliensis is the predominant species in some countries in South America, particularly Brazil.²⁰   

Data describing the current geographic distribution and prevalence of sporotrichosis in the United States are limited. Historically, the disease was reported most commonly in Midwestern states and was associated with outbreaks related to handling Sphagnum moss.^24,25 Epidemiologic studies using health insurance data indicate an average annual incidence of 2.0 cases per million individuals in the United States, with a higher prevalence among women and a median age at diagnosis of 54 years.²⁶ A review of sporotrichosis-associated hospitalizations across the United States from 2000 to 2013 indicated an average hospitalization rate of 0.35 cases per 1 million individuals; rates were higher (0.45 cases per million) in the West and lower (0.15 per million) in the Northeast and in men (0.40 per million).²⁷ Type 2 diabetes, immune-mediated inflammatory disease, and chronic obstructive pulmonary disease are associated with an increased risk for infection and hospitalization.²⁷

Causative Organisms

Sporothrix species are thermally dimorphic fungi that can grow as mold in the environment and as yeast in human tissue. Sporothrix brasiliensis is the only thermodimorphic fungus known to be transmitted directly in its yeast form.²⁸ In other species, inoculation usually occurs after contact with contaminated soil or plant material during gardening, carpentry, or agricultural practices.⁷

Zoonotic transmission of sporotrichosis from animals to humans has been reported from a range of domestic and wild animals and birds but historically has been rare.^5,7,29,30 Recently, the importance of both cat-to-cat (epizootic) and cat-to-human (zoonotic) transmission of S brasiliensis has been recognized, with infection typically following traumatic inoculation after a scratch or bite; less frequently, transmission occurs due to exposure to respiratory droplets or contact with feline exudates.^5,29,31 Sporothrix brasiliensis is responsible for zoonotic epidemics in South America, primarily in Brazil. Transmission occurs among humans, cats, and canines, with felines serving as the primary vector.³² Transmission of this species is particularly common in stray and unneutered male cats that exhibit aggressive behaviors.³³ This species also is thought to be the most virulent Sporothrix species.²¹

Sporothrix brasiliensis can persist on nondisinfected inanimate surfaces, which suggests that fomite transmission can lead to human infection.³¹ The epidemiology of sporotrichosis has transformed in regions where S brasiliensis circulates, with epidemic spread resulting in thousands of cases, whereas in other areas without S brasilinesis, sporotrichosis predominantly occurs sporadically with rare clusters.^1,2,7,15

Sporotrichosis has been the subject of a taxonomic debate in the mycology community.²¹ Sporothrix schenckii sensu lato originally was believed to be the sole fungal pathogen causing sporotrichosis³⁴ but was later divided into S schenckii sensu stricto, Sporothrix globosa, and S brasiliensis.³⁵ More than 60 distinct species now have been described within the Sporothrix genus,^36,37 but the primary species causing human sporotrichosis include S schenckii sensu stricto, S brasiliensis, S globosa, Sporothrix mexicana, and Sporothrix luriei.³⁵ Both S schenckii and S brasiliensis have greater virulence than other Sporothrix species⁴; however, S schenckii causes infections that typically are localized and are milder, while S brasiliensis can lead to more atypical, severe, and disseminated infections^38,39 and can spread epidemically.

Clinical Manifestations

Sporotrichosis has 4 main clinical presentations: cutaneous lymphatic, fixed cutaneous, cutaneous or systemic disseminated, and extracutaneous.^40,41 The most common clinical manifestation is the cutaneous lymphatic form, which predominantly affects the hands and forearms in adults and the face in children.⁷ The primary lesion usually manifests as a unilateral papule, nodule, or pustule that may ulcerate (sporotrichotic chancre), but multiple sites of inoculation are possible. Subsequent lesions may appear in a linear distribution along a regional lymphatic path (sporotrichoid spread). Systemic symptoms and regional lymphadenopathy are uncommon and usually are mild.

The second most common clinical manifestation is the fixed cutaneous form, typically affecting the face, neck, trunk, or legs with a single papule, nodule, or verrucous lesion with no lymphangitic spread.⁷ Usually confined to the inoculation site, the primary lesion may be accompanied by satellite lesions and often presents a diagnostic challenge.

Disseminated sporotrichosis (either cutaneous or systemic) is rare. Disseminated cutaneous sporotrichosis manifests with multiple noncontiguous skin lesions caused by lymphatic and possible hematogenous spread. Lesions may include a combination of papules, pustules, follicular eruptions, crusted plaques, and ulcers that may mimic other systemic infections. Immunoreactive changes such as erythema nodosum, erythema multiforme, or arthritis may accompany skin lesions, most commonly with S brasiliensis infections. Nearly 10% of S brasiliensis infections involve the ocular adnexa, and Parinaud oculoglandular syndrome is commonly described in cases reported in Brazil.^42,43 Disseminated disease usually occurs in immunocompromised hosts; however, despite a focus on HIV co-infection,^8,44 prior epidemiologic research has suggested that diabetes and alcoholism are the most common predisposing factors.⁴⁵ Systemic disseminated sporotrichosis by definition affects at least 2 body systems, most commonly the central nervous system, lungs, and musculoskeletal system (including joints and bone marrow).⁴⁵

Extracutaneous sporotrichosis is rare and often is difficult to diagnose. Risk factors include chronic obstructive pulmonary disease, alcoholism, use of steroid medications, AIDS, solid organ transplantation, and use of tumor necrosis factor α inhibitors. It usually affects bony structures through hematogenous spread in immunocompromised hosts and is associated with a high risk for osteomyelitis due to delayed diagnosis.²

Clinical progression of sporotrichosis usually is slow, and lesions may persist for months or years if untreated. Sporotrichosis should always be considered for atypical, persistent, or treatment-resistant manifestations of nodular or ulcerated skin lesions in endemic regions or acute illness with these symptoms following exposure. Preventing secondary bacterial infection is an important consideration as it can exacerbate disease severity, extend the treatment duration, prolong hospitalization, and increase mortality risk.⁴⁶

Diagnosis

In regions endemic for S brasiliensis, it may be acceptable to commence treatment on clinical suspicion without a definitive diagnosis,²¹ but caution is necessary, as lesions easily can be mistaken for other conditions such as Mycobacterium marinum infections (sporotrichoid lesions) or cutaneous leishmaniasis. Limited availability of molecular diagnostic tools in routine clinical laboratories affects the diagnosis of sporotrichosis and species identification. Direct microscopy on a 10% to 30% potassium hydroxide wet mount has low diagnostic sensitivity and is not recommended⁴⁷; findings typically include cigar-shaped yeast cells (eFigure 1). Biopsy and histopathology also are useful, although in many infections (other than those due to S brasiliensis) there are very few detectable organisms in the tissue. Fluorescent staining of fungi with optical brighteners (eg, Calcofluor, Blankophor) is a useful technique with high sensitivity in clinical specimens on histopathologic and direct examination.⁴⁸

Fungal culture has higher sensitivity and specificity than microscopy and is the gold-standard approach for diagnosis of sporotrichosis (eFigure 2); however, culture cannot differentiate between Sporothrix species and may take more than a month to yield a positive result.⁷ No reliable serologic test for sporotrichosis has been validated, and a standardized antigen assay currently is unavailable.⁴⁹ Serology may be more useful for patients who present with systemic disease or have persistently negative culture results despite a high index of suspicion. 

A recent study evaluated the effectiveness of a lateral flow assay for detecting anti-Sporothrix antibodies, demonstrating the potential for its use as a rapid diagnostic test.⁵⁰ Investigating different molecular methods to increase the sensitivity and specificity of diagnosis and distinguish Sporothrix species has been a focus of recent research, with a preference for polymerase chain reaction (PCR)–based genotypic methods.^13,51 Recent advances in diagnostic testing include the development of multiplex PCR,⁵² culture-independent PCR techniques,⁵³ and matrix-assisted laser desorption/ionization–time of flight mass spectrometry,⁵⁴ each with varying clinical and practical applicability. Specialized testing can be beneficial for patients who have a poor therapeutic response to standard treatment, guide antifungal treatment choices, and identify epidemiologic disease and transmission patterns.²¹

Although rarely performed, antifungal susceptibility testing may be useful in guiding therapy to improve patient outcomes, particularly in the context of treatment failure, which has been documented with isolates exhibiting high minimal inhibitory concentrations (MICs) to first-line therapy and a poor clinical response.^55,56 Proposed mechanisms of resistance include increased cellular melanin ­production, which protects against oxidative stress and reduces antifungal activity.⁵⁶ Antifungal susceptibility profiles for therapeutics vary across Sporothrix species; for example, S brasiliensis generally shows lower MICs to itraconazole and terbinafine compared with S schenckii and S globosa, and S schenckii has shown a high MIC to itraconazole, as reflected in MIC distribution studies and epidemiologic cutoff values for antifungal agents.^55,57-59 However, specific breakpoints for different Sporothrix species have not been determined.⁶⁰ Robust clinical studies are needed to determine the correlation of in vitro MICs to clinical outcomes to assess the utility of antifungal susceptibility testing for Sporothrix species.

Management

Treatment of sporotrichosis is guided by clinical presentation, host immune status, and species identification. Management can be challenging in cases with an atypical or delayed diagnosis and limited access to molecular testing methods. Itraconazole is the first-line therapy for management of cutaneous sporotrichosis. It is regarded as safe, effective, well tolerated, and easily administered, with doses ranging from 100 mg in mild cases to 400 mg (with daily or twice-daily dosing).⁶¹ Treatment usually is for 3 to 6 months and should continue for 1 month after complete clinical resolution is achieved⁶²; however, some cases of S brasiliensis infection require longer treatment, and complex or disseminated cases may require therapy for up to 12 months.⁶¹ Itraconazole is contraindicated in pregnancy and has many drug interactions (through cytochrome P450 inhibition) that may preclude administration, particularly in elderly populations. Therapeutic drug monitoring is recommended for prolonged or high-dose therapy, with periodic liver function testing to reduce the risk for toxicity. Itraconazole should be administered with food, and concurrent use of antacids or proton pump inhibitors should be avoided.⁶¹

Oral terbinafine (250 mg daily) can be considered as an effective alternative to treat cutaneous disease.⁶³ Particularly in resource-limited settings, potassium iodide is an affordable and effective treatment for cutaneous sporotrichosis, administered as a saturated oral solution,⁶⁴ but due to adverse effects such as severe nausea, the daily dose should be increased slowly each day to ensure tolerance.

Amphotericin B is the treatment of choice for severe and treatment-resistant cases of sporotrichosis as well as for immunocompromised patients.^21,61 In patients with HIV, a longer treatment course is recommended with oversight from an infectious diseases specialist and usually is followed by a 12-month course of itraconazole after completion of initial therapy.⁶¹ Surgical excision infrequently is recommended but can be used in combination with another treatment modality and may be useful with a slow or incomplete response to medical therapy. Thermotherapy involves direct application of heat to cutaneous lesions and may be considered for small and localized lesions, particularly if antifungal agents are contraindicated or poorly tolerated.⁶¹ Public health measures include promoting case detection through practitioner education and patient awareness in endemic regions, as well as zoonotic control of infected animals to manage sporotrichosis.

Final Thoughts

Sporotrichosis is a fungal infection with growing public health significance. While the global disease burden is unknown, rising case numbers and geographic spread likely reflect a complex interaction between humans, the environment, and animals, exemplified by the spread of feline-associated infection due to S brasiliensis in South America.²⁸ Cases of S brasiliensis infection after importation of an affected cat have been detected outside South America, and clinicians should be alert for introduction to the United States. Strengthening genotypic and phenotypic diagnostic capabilities will allow species identification and guide treatment and management. Disease surveillance and operational research will inform public health approaches to control sporotrichosis worldwide.

Sporotrichosis is an implantation mycosis that classically manifests as a localized skin and subcutaneous fungal infection but may disseminate to other parts of the body.¹ It is caused by several species within the Sporothrix genus² and is associated with varying clinical manifestations, geographic distributions, virulence profiles, and antifungal susceptibility patterns.^3,4 Transmission of the fungus can involve inoculation from wild or domestic animals (eg, cats).^5,6 Occupations such as landscaping and gardening or elements in the environment (eg, soil, plant fragments) also can be sources of exposure.^7,8

Sporotrichosis is recognized by the World Health Organization as a neglected tropical disease that warrants global advocacy to prevent infections and improve patient outcomes.^9,10 It carries substantial stigma and socioeconomic burden.^11,12 Diagnostics, species identification, and antifungal susceptibility testing often are limited, particularly in resource-limited settings.¹³ In this article, we outline steps to diagnose and manage sporotrichosis to improve care for affected patients globally.

Epidemiology

Sporotrichosis occurs worldwide but is most common in tropical and subtropical regions.^14,15 Outbreaks and clusters of sporotrichosis have been observed across North, Central, and South America as well as in southern Africa and Asia. The estimated annual incidence is 40,000 cases worldwide,^16-20 but global case counts likely are underestimated due to limited surveillance data and diagnostic capability.²¹

On the Asian subcontinent, Sporothrix globosa is the predominant causative species of sporotrichosis, typically via contaminated plant material²²; however, at least 1 outbreak has been associated with severe flooding.²³ In Africa, infections are most commonly caused by Sporothrix schenckii sensu stricto through a similar transmission route. Across Central America, S schenckii sensu stricto is the predominant causative species; however, Sporothrix brasiliensis is the predominant species in some countries in South America, particularly Brazil.²⁰   

Data describing the current geographic distribution and prevalence of sporotrichosis in the United States are limited. Historically, the disease was reported most commonly in Midwestern states and was associated with outbreaks related to handling Sphagnum moss.^24,25 Epidemiologic studies using health insurance data indicate an average annual incidence of 2.0 cases per million individuals in the United States, with a higher prevalence among women and a median age at diagnosis of 54 years.²⁶ A review of sporotrichosis-associated hospitalizations across the United States from 2000 to 2013 indicated an average hospitalization rate of 0.35 cases per 1 million individuals; rates were higher (0.45 cases per million) in the West and lower (0.15 per million) in the Northeast and in men (0.40 per million).²⁷ Type 2 diabetes, immune-mediated inflammatory disease, and chronic obstructive pulmonary disease are associated with an increased risk for infection and hospitalization.²⁷

Causative Organisms

Sporothrix species are thermally dimorphic fungi that can grow as mold in the environment and as yeast in human tissue. Sporothrix brasiliensis is the only thermodimorphic fungus known to be transmitted directly in its yeast form.²⁸ In other species, inoculation usually occurs after contact with contaminated soil or plant material during gardening, carpentry, or agricultural practices.⁷

Zoonotic transmission of sporotrichosis from animals to humans has been reported from a range of domestic and wild animals and birds but historically has been rare.^5,7,29,30 Recently, the importance of both cat-to-cat (epizootic) and cat-to-human (zoonotic) transmission of S brasiliensis has been recognized, with infection typically following traumatic inoculation after a scratch or bite; less frequently, transmission occurs due to exposure to respiratory droplets or contact with feline exudates.^5,29,31 Sporothrix brasiliensis is responsible for zoonotic epidemics in South America, primarily in Brazil. Transmission occurs among humans, cats, and canines, with felines serving as the primary vector.³² Transmission of this species is particularly common in stray and unneutered male cats that exhibit aggressive behaviors.³³ This species also is thought to be the most virulent Sporothrix species.²¹

Sporothrix brasiliensis can persist on nondisinfected inanimate surfaces, which suggests that fomite transmission can lead to human infection.³¹ The epidemiology of sporotrichosis has transformed in regions where S brasiliensis circulates, with epidemic spread resulting in thousands of cases, whereas in other areas without S brasilinesis, sporotrichosis predominantly occurs sporadically with rare clusters.^1,2,7,15

Sporotrichosis has been the subject of a taxonomic debate in the mycology community.²¹ Sporothrix schenckii sensu lato originally was believed to be the sole fungal pathogen causing sporotrichosis³⁴ but was later divided into S schenckii sensu stricto, Sporothrix globosa, and S brasiliensis.³⁵ More than 60 distinct species now have been described within the Sporothrix genus,^36,37 but the primary species causing human sporotrichosis include S schenckii sensu stricto, S brasiliensis, S globosa, Sporothrix mexicana, and Sporothrix luriei.³⁵ Both S schenckii and S brasiliensis have greater virulence than other Sporothrix species⁴; however, S schenckii causes infections that typically are localized and are milder, while S brasiliensis can lead to more atypical, severe, and disseminated infections^38,39 and can spread epidemically.

Clinical Manifestations

Sporotrichosis has 4 main clinical presentations: cutaneous lymphatic, fixed cutaneous, cutaneous or systemic disseminated, and extracutaneous.^40,41 The most common clinical manifestation is the cutaneous lymphatic form, which predominantly affects the hands and forearms in adults and the face in children.⁷ The primary lesion usually manifests as a unilateral papule, nodule, or pustule that may ulcerate (sporotrichotic chancre), but multiple sites of inoculation are possible. Subsequent lesions may appear in a linear distribution along a regional lymphatic path (sporotrichoid spread). Systemic symptoms and regional lymphadenopathy are uncommon and usually are mild.

The second most common clinical manifestation is the fixed cutaneous form, typically affecting the face, neck, trunk, or legs with a single papule, nodule, or verrucous lesion with no lymphangitic spread.⁷ Usually confined to the inoculation site, the primary lesion may be accompanied by satellite lesions and often presents a diagnostic challenge.

Disseminated sporotrichosis (either cutaneous or systemic) is rare. Disseminated cutaneous sporotrichosis manifests with multiple noncontiguous skin lesions caused by lymphatic and possible hematogenous spread. Lesions may include a combination of papules, pustules, follicular eruptions, crusted plaques, and ulcers that may mimic other systemic infections. Immunoreactive changes such as erythema nodosum, erythema multiforme, or arthritis may accompany skin lesions, most commonly with S brasiliensis infections. Nearly 10% of S brasiliensis infections involve the ocular adnexa, and Parinaud oculoglandular syndrome is commonly described in cases reported in Brazil.^42,43 Disseminated disease usually occurs in immunocompromised hosts; however, despite a focus on HIV co-infection,^8,44 prior epidemiologic research has suggested that diabetes and alcoholism are the most common predisposing factors.⁴⁵ Systemic disseminated sporotrichosis by definition affects at least 2 body systems, most commonly the central nervous system, lungs, and musculoskeletal system (including joints and bone marrow).⁴⁵

Extracutaneous sporotrichosis is rare and often is difficult to diagnose. Risk factors include chronic obstructive pulmonary disease, alcoholism, use of steroid medications, AIDS, solid organ transplantation, and use of tumor necrosis factor α inhibitors. It usually affects bony structures through hematogenous spread in immunocompromised hosts and is associated with a high risk for osteomyelitis due to delayed diagnosis.²

Clinical progression of sporotrichosis usually is slow, and lesions may persist for months or years if untreated. Sporotrichosis should always be considered for atypical, persistent, or treatment-resistant manifestations of nodular or ulcerated skin lesions in endemic regions or acute illness with these symptoms following exposure. Preventing secondary bacterial infection is an important consideration as it can exacerbate disease severity, extend the treatment duration, prolong hospitalization, and increase mortality risk.⁴⁶

Diagnosis

In regions endemic for S brasiliensis, it may be acceptable to commence treatment on clinical suspicion without a definitive diagnosis,²¹ but caution is necessary, as lesions easily can be mistaken for other conditions such as Mycobacterium marinum infections (sporotrichoid lesions) or cutaneous leishmaniasis. Limited availability of molecular diagnostic tools in routine clinical laboratories affects the diagnosis of sporotrichosis and species identification. Direct microscopy on a 10% to 30% potassium hydroxide wet mount has low diagnostic sensitivity and is not recommended⁴⁷; findings typically include cigar-shaped yeast cells (eFigure 1). Biopsy and histopathology also are useful, although in many infections (other than those due to S brasiliensis) there are very few detectable organisms in the tissue. Fluorescent staining of fungi with optical brighteners (eg, Calcofluor, Blankophor) is a useful technique with high sensitivity in clinical specimens on histopathologic and direct examination.⁴⁸

Fungal culture has higher sensitivity and specificity than microscopy and is the gold-standard approach for diagnosis of sporotrichosis (eFigure 2); however, culture cannot differentiate between Sporothrix species and may take more than a month to yield a positive result.⁷ No reliable serologic test for sporotrichosis has been validated, and a standardized antigen assay currently is unavailable.⁴⁹ Serology may be more useful for patients who present with systemic disease or have persistently negative culture results despite a high index of suspicion. 

A recent study evaluated the effectiveness of a lateral flow assay for detecting anti-Sporothrix antibodies, demonstrating the potential for its use as a rapid diagnostic test.⁵⁰ Investigating different molecular methods to increase the sensitivity and specificity of diagnosis and distinguish Sporothrix species has been a focus of recent research, with a preference for polymerase chain reaction (PCR)–based genotypic methods.^13,51 Recent advances in diagnostic testing include the development of multiplex PCR,⁵² culture-independent PCR techniques,⁵³ and matrix-assisted laser desorption/ionization–time of flight mass spectrometry,⁵⁴ each with varying clinical and practical applicability. Specialized testing can be beneficial for patients who have a poor therapeutic response to standard treatment, guide antifungal treatment choices, and identify epidemiologic disease and transmission patterns.²¹

Although rarely performed, antifungal susceptibility testing may be useful in guiding therapy to improve patient outcomes, particularly in the context of treatment failure, which has been documented with isolates exhibiting high minimal inhibitory concentrations (MICs) to first-line therapy and a poor clinical response.^55,56 Proposed mechanisms of resistance include increased cellular melanin ­production, which protects against oxidative stress and reduces antifungal activity.⁵⁶ Antifungal susceptibility profiles for therapeutics vary across Sporothrix species; for example, S brasiliensis generally shows lower MICs to itraconazole and terbinafine compared with S schenckii and S globosa, and S schenckii has shown a high MIC to itraconazole, as reflected in MIC distribution studies and epidemiologic cutoff values for antifungal agents.^55,57-59 However, specific breakpoints for different Sporothrix species have not been determined.⁶⁰ Robust clinical studies are needed to determine the correlation of in vitro MICs to clinical outcomes to assess the utility of antifungal susceptibility testing for Sporothrix species.

Management

Treatment of sporotrichosis is guided by clinical presentation, host immune status, and species identification. Management can be challenging in cases with an atypical or delayed diagnosis and limited access to molecular testing methods. Itraconazole is the first-line therapy for management of cutaneous sporotrichosis. It is regarded as safe, effective, well tolerated, and easily administered, with doses ranging from 100 mg in mild cases to 400 mg (with daily or twice-daily dosing).⁶¹ Treatment usually is for 3 to 6 months and should continue for 1 month after complete clinical resolution is achieved⁶²; however, some cases of S brasiliensis infection require longer treatment, and complex or disseminated cases may require therapy for up to 12 months.⁶¹ Itraconazole is contraindicated in pregnancy and has many drug interactions (through cytochrome P450 inhibition) that may preclude administration, particularly in elderly populations. Therapeutic drug monitoring is recommended for prolonged or high-dose therapy, with periodic liver function testing to reduce the risk for toxicity. Itraconazole should be administered with food, and concurrent use of antacids or proton pump inhibitors should be avoided.⁶¹

Oral terbinafine (250 mg daily) can be considered as an effective alternative to treat cutaneous disease.⁶³ Particularly in resource-limited settings, potassium iodide is an affordable and effective treatment for cutaneous sporotrichosis, administered as a saturated oral solution,⁶⁴ but due to adverse effects such as severe nausea, the daily dose should be increased slowly each day to ensure tolerance.

Amphotericin B is the treatment of choice for severe and treatment-resistant cases of sporotrichosis as well as for immunocompromised patients.^21,61 In patients with HIV, a longer treatment course is recommended with oversight from an infectious diseases specialist and usually is followed by a 12-month course of itraconazole after completion of initial therapy.⁶¹ Surgical excision infrequently is recommended but can be used in combination with another treatment modality and may be useful with a slow or incomplete response to medical therapy. Thermotherapy involves direct application of heat to cutaneous lesions and may be considered for small and localized lesions, particularly if antifungal agents are contraindicated or poorly tolerated.⁶¹ Public health measures include promoting case detection through practitioner education and patient awareness in endemic regions, as well as zoonotic control of infected animals to manage sporotrichosis.

Final Thoughts

Sporotrichosis is a fungal infection with growing public health significance. While the global disease burden is unknown, rising case numbers and geographic spread likely reflect a complex interaction between humans, the environment, and animals, exemplified by the spread of feline-associated infection due to S brasiliensis in South America.²⁸ Cases of S brasiliensis infection after importation of an affected cat have been detected outside South America, and clinicians should be alert for introduction to the United States. Strengthening genotypic and phenotypic diagnostic capabilities will allow species identification and guide treatment and management. Disease surveillance and operational research will inform public health approaches to control sporotrichosis worldwide.

Sporotrichosis is an implantation mycosis that classically manifests as a localized skin and subcutaneous fungal infection but may disseminate to other parts of the body.¹ It is caused by several species within the Sporothrix genus² and is associated with varying clinical manifestations, geographic distributions, virulence profiles, and antifungal susceptibility patterns.^3,4 Transmission of the fungus can involve inoculation from wild or domestic animals (eg, cats).^5,6 Occupations such as landscaping and gardening or elements in the environment (eg, soil, plant fragments) also can be sources of exposure.^7,8

Sporotrichosis is recognized by the World Health Organization as a neglected tropical disease that warrants global advocacy to prevent infections and improve patient outcomes.^9,10 It carries substantial stigma and socioeconomic burden.^11,12 Diagnostics, species identification, and antifungal susceptibility testing often are limited, particularly in resource-limited settings.¹³ In this article, we outline steps to diagnose and manage sporotrichosis to improve care for affected patients globally.

Epidemiology

Sporotrichosis occurs worldwide but is most common in tropical and subtropical regions.^14,15 Outbreaks and clusters of sporotrichosis have been observed across North, Central, and South America as well as in southern Africa and Asia. The estimated annual incidence is 40,000 cases worldwide,^16-20 but global case counts likely are underestimated due to limited surveillance data and diagnostic capability.²¹

On the Asian subcontinent, Sporothrix globosa is the predominant causative species of sporotrichosis, typically via contaminated plant material²²; however, at least 1 outbreak has been associated with severe flooding.²³ In Africa, infections are most commonly caused by Sporothrix schenckii sensu stricto through a similar transmission route. Across Central America, S schenckii sensu stricto is the predominant causative species; however, Sporothrix brasiliensis is the predominant species in some countries in South America, particularly Brazil.²⁰   

Data describing the current geographic distribution and prevalence of sporotrichosis in the United States are limited. Historically, the disease was reported most commonly in Midwestern states and was associated with outbreaks related to handling Sphagnum moss.^24,25 Epidemiologic studies using health insurance data indicate an average annual incidence of 2.0 cases per million individuals in the United States, with a higher prevalence among women and a median age at diagnosis of 54 years.²⁶ A review of sporotrichosis-associated hospitalizations across the United States from 2000 to 2013 indicated an average hospitalization rate of 0.35 cases per 1 million individuals; rates were higher (0.45 cases per million) in the West and lower (0.15 per million) in the Northeast and in men (0.40 per million).²⁷ Type 2 diabetes, immune-mediated inflammatory disease, and chronic obstructive pulmonary disease are associated with an increased risk for infection and hospitalization.²⁷

Causative Organisms

Sporothrix species are thermally dimorphic fungi that can grow as mold in the environment and as yeast in human tissue. Sporothrix brasiliensis is the only thermodimorphic fungus known to be transmitted directly in its yeast form.²⁸ In other species, inoculation usually occurs after contact with contaminated soil or plant material during gardening, carpentry, or agricultural practices.⁷

Zoonotic transmission of sporotrichosis from animals to humans has been reported from a range of domestic and wild animals and birds but historically has been rare.^5,7,29,30 Recently, the importance of both cat-to-cat (epizootic) and cat-to-human (zoonotic) transmission of S brasiliensis has been recognized, with infection typically following traumatic inoculation after a scratch or bite; less frequently, transmission occurs due to exposure to respiratory droplets or contact with feline exudates.^5,29,31 Sporothrix brasiliensis is responsible for zoonotic epidemics in South America, primarily in Brazil. Transmission occurs among humans, cats, and canines, with felines serving as the primary vector.³² Transmission of this species is particularly common in stray and unneutered male cats that exhibit aggressive behaviors.³³ This species also is thought to be the most virulent Sporothrix species.²¹

Sporothrix brasiliensis can persist on nondisinfected inanimate surfaces, which suggests that fomite transmission can lead to human infection.³¹ The epidemiology of sporotrichosis has transformed in regions where S brasiliensis circulates, with epidemic spread resulting in thousands of cases, whereas in other areas without S brasilinesis, sporotrichosis predominantly occurs sporadically with rare clusters.^1,2,7,15

Sporotrichosis has been the subject of a taxonomic debate in the mycology community.²¹ Sporothrix schenckii sensu lato originally was believed to be the sole fungal pathogen causing sporotrichosis³⁴ but was later divided into S schenckii sensu stricto, Sporothrix globosa, and S brasiliensis.³⁵ More than 60 distinct species now have been described within the Sporothrix genus,^36,37 but the primary species causing human sporotrichosis include S schenckii sensu stricto, S brasiliensis, S globosa, Sporothrix mexicana, and Sporothrix luriei.³⁵ Both S schenckii and S brasiliensis have greater virulence than other Sporothrix species⁴; however, S schenckii causes infections that typically are localized and are milder, while S brasiliensis can lead to more atypical, severe, and disseminated infections^38,39 and can spread epidemically.

Clinical Manifestations

Sporotrichosis has 4 main clinical presentations: cutaneous lymphatic, fixed cutaneous, cutaneous or systemic disseminated, and extracutaneous.^40,41 The most common clinical manifestation is the cutaneous lymphatic form, which predominantly affects the hands and forearms in adults and the face in children.⁷ The primary lesion usually manifests as a unilateral papule, nodule, or pustule that may ulcerate (sporotrichotic chancre), but multiple sites of inoculation are possible. Subsequent lesions may appear in a linear distribution along a regional lymphatic path (sporotrichoid spread). Systemic symptoms and regional lymphadenopathy are uncommon and usually are mild.

The second most common clinical manifestation is the fixed cutaneous form, typically affecting the face, neck, trunk, or legs with a single papule, nodule, or verrucous lesion with no lymphangitic spread.⁷ Usually confined to the inoculation site, the primary lesion may be accompanied by satellite lesions and often presents a diagnostic challenge.

Disseminated sporotrichosis (either cutaneous or systemic) is rare. Disseminated cutaneous sporotrichosis manifests with multiple noncontiguous skin lesions caused by lymphatic and possible hematogenous spread. Lesions may include a combination of papules, pustules, follicular eruptions, crusted plaques, and ulcers that may mimic other systemic infections. Immunoreactive changes such as erythema nodosum, erythema multiforme, or arthritis may accompany skin lesions, most commonly with S brasiliensis infections. Nearly 10% of S brasiliensis infections involve the ocular adnexa, and Parinaud oculoglandular syndrome is commonly described in cases reported in Brazil.^42,43 Disseminated disease usually occurs in immunocompromised hosts; however, despite a focus on HIV co-infection,^8,44 prior epidemiologic research has suggested that diabetes and alcoholism are the most common predisposing factors.⁴⁵ Systemic disseminated sporotrichosis by definition affects at least 2 body systems, most commonly the central nervous system, lungs, and musculoskeletal system (including joints and bone marrow).⁴⁵

Extracutaneous sporotrichosis is rare and often is difficult to diagnose. Risk factors include chronic obstructive pulmonary disease, alcoholism, use of steroid medications, AIDS, solid organ transplantation, and use of tumor necrosis factor α inhibitors. It usually affects bony structures through hematogenous spread in immunocompromised hosts and is associated with a high risk for osteomyelitis due to delayed diagnosis.²

Clinical progression of sporotrichosis usually is slow, and lesions may persist for months or years if untreated. Sporotrichosis should always be considered for atypical, persistent, or treatment-resistant manifestations of nodular or ulcerated skin lesions in endemic regions or acute illness with these symptoms following exposure. Preventing secondary bacterial infection is an important consideration as it can exacerbate disease severity, extend the treatment duration, prolong hospitalization, and increase mortality risk.⁴⁶

Diagnosis

In regions endemic for S brasiliensis, it may be acceptable to commence treatment on clinical suspicion without a definitive diagnosis,²¹ but caution is necessary, as lesions easily can be mistaken for other conditions such as Mycobacterium marinum infections (sporotrichoid lesions) or cutaneous leishmaniasis. Limited availability of molecular diagnostic tools in routine clinical laboratories affects the diagnosis of sporotrichosis and species identification. Direct microscopy on a 10% to 30% potassium hydroxide wet mount has low diagnostic sensitivity and is not recommended⁴⁷; findings typically include cigar-shaped yeast cells (eFigure 1). Biopsy and histopathology also are useful, although in many infections (other than those due to S brasiliensis) there are very few detectable organisms in the tissue. Fluorescent staining of fungi with optical brighteners (eg, Calcofluor, Blankophor) is a useful technique with high sensitivity in clinical specimens on histopathologic and direct examination.⁴⁸

Fungal culture has higher sensitivity and specificity than microscopy and is the gold-standard approach for diagnosis of sporotrichosis (eFigure 2); however, culture cannot differentiate between Sporothrix species and may take more than a month to yield a positive result.⁷ No reliable serologic test for sporotrichosis has been validated, and a standardized antigen assay currently is unavailable.⁴⁹ Serology may be more useful for patients who present with systemic disease or have persistently negative culture results despite a high index of suspicion. 

A recent study evaluated the effectiveness of a lateral flow assay for detecting anti-Sporothrix antibodies, demonstrating the potential for its use as a rapid diagnostic test.⁵⁰ Investigating different molecular methods to increase the sensitivity and specificity of diagnosis and distinguish Sporothrix species has been a focus of recent research, with a preference for polymerase chain reaction (PCR)–based genotypic methods.^13,51 Recent advances in diagnostic testing include the development of multiplex PCR,⁵² culture-independent PCR techniques,⁵³ and matrix-assisted laser desorption/ionization–time of flight mass spectrometry,⁵⁴ each with varying clinical and practical applicability. Specialized testing can be beneficial for patients who have a poor therapeutic response to standard treatment, guide antifungal treatment choices, and identify epidemiologic disease and transmission patterns.²¹

Although rarely performed, antifungal susceptibility testing may be useful in guiding therapy to improve patient outcomes, particularly in the context of treatment failure, which has been documented with isolates exhibiting high minimal inhibitory concentrations (MICs) to first-line therapy and a poor clinical response.^55,56 Proposed mechanisms of resistance include increased cellular melanin ­production, which protects against oxidative stress and reduces antifungal activity.⁵⁶ Antifungal susceptibility profiles for therapeutics vary across Sporothrix species; for example, S brasiliensis generally shows lower MICs to itraconazole and terbinafine compared with S schenckii and S globosa, and S schenckii has shown a high MIC to itraconazole, as reflected in MIC distribution studies and epidemiologic cutoff values for antifungal agents.^55,57-59 However, specific breakpoints for different Sporothrix species have not been determined.⁶⁰ Robust clinical studies are needed to determine the correlation of in vitro MICs to clinical outcomes to assess the utility of antifungal susceptibility testing for Sporothrix species.

Management

Treatment of sporotrichosis is guided by clinical presentation, host immune status, and species identification. Management can be challenging in cases with an atypical or delayed diagnosis and limited access to molecular testing methods. Itraconazole is the first-line therapy for management of cutaneous sporotrichosis. It is regarded as safe, effective, well tolerated, and easily administered, with doses ranging from 100 mg in mild cases to 400 mg (with daily or twice-daily dosing).⁶¹ Treatment usually is for 3 to 6 months and should continue for 1 month after complete clinical resolution is achieved⁶²; however, some cases of S brasiliensis infection require longer treatment, and complex or disseminated cases may require therapy for up to 12 months.⁶¹ Itraconazole is contraindicated in pregnancy and has many drug interactions (through cytochrome P450 inhibition) that may preclude administration, particularly in elderly populations. Therapeutic drug monitoring is recommended for prolonged or high-dose therapy, with periodic liver function testing to reduce the risk for toxicity. Itraconazole should be administered with food, and concurrent use of antacids or proton pump inhibitors should be avoided.⁶¹

Oral terbinafine (250 mg daily) can be considered as an effective alternative to treat cutaneous disease.⁶³ Particularly in resource-limited settings, potassium iodide is an affordable and effective treatment for cutaneous sporotrichosis, administered as a saturated oral solution,⁶⁴ but due to adverse effects such as severe nausea, the daily dose should be increased slowly each day to ensure tolerance.

Amphotericin B is the treatment of choice for severe and treatment-resistant cases of sporotrichosis as well as for immunocompromised patients.^21,61 In patients with HIV, a longer treatment course is recommended with oversight from an infectious diseases specialist and usually is followed by a 12-month course of itraconazole after completion of initial therapy.⁶¹ Surgical excision infrequently is recommended but can be used in combination with another treatment modality and may be useful with a slow or incomplete response to medical therapy. Thermotherapy involves direct application of heat to cutaneous lesions and may be considered for small and localized lesions, particularly if antifungal agents are contraindicated or poorly tolerated.⁶¹ Public health measures include promoting case detection through practitioner education and patient awareness in endemic regions, as well as zoonotic control of infected animals to manage sporotrichosis.

Final Thoughts

Sporotrichosis is a fungal infection with growing public health significance. While the global disease burden is unknown, rising case numbers and geographic spread likely reflect a complex interaction between humans, the environment, and animals, exemplified by the spread of feline-associated infection due to S brasiliensis in South America.²⁸ Cases of S brasiliensis infection after importation of an affected cat have been detected outside South America, and clinicians should be alert for introduction to the United States. Strengthening genotypic and phenotypic diagnostic capabilities will allow species identification and guide treatment and management. Disease surveillance and operational research will inform public health approaches to control sporotrichosis worldwide.