Contact Dermatitis

There are limited clinical data concerning inpatient and emergency department (ED) dermatologic consultations. The indications for these consultations vary widely, but in one study (N=271), it was found that 21% of inpatient consultations were for contact dermatitis and 10% were for drug eruptions.¹ In the same study, 77% of patients who required a dermatology consultation eventually were given a different diagnosis or change in treatment after consultation. For example, of all consultations for suspected cellulitis, only 10% were confirmed after dermatology evaluation.¹

Hospitalists and emergency physicians continue to struggle with the assessment of dermatologic conditions, often consulting dermatology whenever a patient has a “rash” or skin concern. Dermatology is still not emphasized in medical education and often is taught to most medical students in an abbreviated fashion, which results in physicians feeling ill-equipped to deal with any dermatologic condition—either mundane or potentially life-threatening. A study in 2016 showed that a monthly lecture series given to hospitalists over the course of 5 years did not improve diagnostic accuracy in patients who were admitted with skin manifestations.² This further shows that there is a need for dermatologic experts in the hospital.

We need to develop better guidelines for physicians in the ED and on inpatient units to guide them on appropriate use of dermatologic consultation outside the ambulatory office and the clinic. A 2013 study showed that patients often were discharged immediately after a dermatologic consultation, furthering our hypothesis that many inpatient consultations can be delayed until after discharge.³

In an era in which medical costs are soaring and there is constant surveillance for ways to reduce costs without impairing quality of care, limiting unnecessary specialty consultations should be embraced. In 2009, $1.8 billion in Medicare claims was paid for dermatology-related admissions.³ A substantial savings to Medicare consulting fees for certain diagnoses, such as cellulitis or contact dermatitis, could be realized if patients were referred for outpatient assessment and treatment. In a study of 271 consultations, 54 patients also had a skin biopsy, which further increases dollars spent on inpatient care and is (usually) something that can be performed in the outpatient setting.¹ In another study, the more common recommended treatments were topical corticosteroids and supportive educational measures for patients and hospital staff,³ which further substantiates that most dermatology consultations are not truly emergent and can wait for outpatient consultation.

In addition, we are dealing with the COVID-19 pandemic in our hospitals and EDs. Many physicians, including dermatologists, would prefer to avoid unnecessary exposure to SARS-CoV-2 on inpatient units and in the ED. It certainly would be preferable to require consultants to come in to evaluate patients only when they truly need to be seen while in the hospital.

There also is limited dermatology training in other specialties, and the dermatology team can help fill this gap with educational programs and one-on-one teaching. Hospital teams have signaled this need, but there has been limited success with multiple teaching opportunities.⁴

We believe that this need for inpatient dermatology services can be filled with the newer subspecialty of hospital dermatology, which is not commonly present at most hospitals; a reason why the subspecialty has not been more popular is that there are few available data in the form of randomized clinical trials that can guide inpatient dermatologists with the care of rare hospital skin diseases.⁵ Having a dermatologic hospitalist available might allow for patients to be seen more readily, which ultimately will save lives and health care dollars and would increase real-time teaching and education for house staff, nursing, and attendings at the bedside.

In a 2018 article,⁶ it was postulated that quicker diagnosis of pseudocellulitis and initiation of antibiotics to treat this condition would save the US health care system $210 million annually. We believe that pseudocellulitis would be best evaluated by inpatient dermatology teams, thereby avoiding costly dermatologic consultations, at an average rate of $138.89.⁶

Morbilliform drug eruptions are among the most common skin conditions seen in the hospital; approximately 95% of cases are an uncomplicated reaction to a medication or virus. Data show that many of these consultations might be unnecessary.⁷

Our institution (Hackensack University Medical Center, New Jersey) is a tertiary hospital that also is connected with a major cancer center. Given this connection, skin eruptions due to chemotherapy and radiation are common. The treatment of drug eruptions, graft-vs-host disease, and other oncologic or drug-related eruptions should be within the scope of practice of our hospitalists, but these cases frequently involve dermatologic consultation.

We constructed a consultation flowchart (Figure) to help guide the triage of patients in need of dermatologic evaluation by inpatient teams and possibly to avoid unnecessary consultation fees. The manner in which this—or any flowchart or teaching aid—is conveyed to hospital personnel is critical so that these tools are not perceived as patronizing or confrontational. In our flowchart, we list emergent dermatologic conditions that we believe are appropriate for dermatology consultation including erythrodermic psoriasis, bullous pemphigoid flare, and Stevens-Johnson syndrome/toxic epidermal necrolysis.

We believe that the flowchart can educate inpatient medical teams about appropriate dermatology consultation. Use of the flowchart also may decrease unnecessary consultations, which ultimately will lower health care spending overall.

There are limited clinical data concerning inpatient and emergency department (ED) dermatologic consultations. The indications for these consultations vary widely, but in one study (N=271), it was found that 21% of inpatient consultations were for contact dermatitis and 10% were for drug eruptions.¹ In the same study, 77% of patients who required a dermatology consultation eventually were given a different diagnosis or change in treatment after consultation. For example, of all consultations for suspected cellulitis, only 10% were confirmed after dermatology evaluation.¹

Hospitalists and emergency physicians continue to struggle with the assessment of dermatologic conditions, often consulting dermatology whenever a patient has a “rash” or skin concern. Dermatology is still not emphasized in medical education and often is taught to most medical students in an abbreviated fashion, which results in physicians feeling ill-equipped to deal with any dermatologic condition—either mundane or potentially life-threatening. A study in 2016 showed that a monthly lecture series given to hospitalists over the course of 5 years did not improve diagnostic accuracy in patients who were admitted with skin manifestations.² This further shows that there is a need for dermatologic experts in the hospital.

We need to develop better guidelines for physicians in the ED and on inpatient units to guide them on appropriate use of dermatologic consultation outside the ambulatory office and the clinic. A 2013 study showed that patients often were discharged immediately after a dermatologic consultation, furthering our hypothesis that many inpatient consultations can be delayed until after discharge.³

In an era in which medical costs are soaring and there is constant surveillance for ways to reduce costs without impairing quality of care, limiting unnecessary specialty consultations should be embraced. In 2009, $1.8 billion in Medicare claims was paid for dermatology-related admissions.³ A substantial savings to Medicare consulting fees for certain diagnoses, such as cellulitis or contact dermatitis, could be realized if patients were referred for outpatient assessment and treatment. In a study of 271 consultations, 54 patients also had a skin biopsy, which further increases dollars spent on inpatient care and is (usually) something that can be performed in the outpatient setting.¹ In another study, the more common recommended treatments were topical corticosteroids and supportive educational measures for patients and hospital staff,³ which further substantiates that most dermatology consultations are not truly emergent and can wait for outpatient consultation.

In addition, we are dealing with the COVID-19 pandemic in our hospitals and EDs. Many physicians, including dermatologists, would prefer to avoid unnecessary exposure to SARS-CoV-2 on inpatient units and in the ED. It certainly would be preferable to require consultants to come in to evaluate patients only when they truly need to be seen while in the hospital.

There also is limited dermatology training in other specialties, and the dermatology team can help fill this gap with educational programs and one-on-one teaching. Hospital teams have signaled this need, but there has been limited success with multiple teaching opportunities.⁴

We believe that this need for inpatient dermatology services can be filled with the newer subspecialty of hospital dermatology, which is not commonly present at most hospitals; a reason why the subspecialty has not been more popular is that there are few available data in the form of randomized clinical trials that can guide inpatient dermatologists with the care of rare hospital skin diseases.⁵ Having a dermatologic hospitalist available might allow for patients to be seen more readily, which ultimately will save lives and health care dollars and would increase real-time teaching and education for house staff, nursing, and attendings at the bedside.

In a 2018 article,⁶ it was postulated that quicker diagnosis of pseudocellulitis and initiation of antibiotics to treat this condition would save the US health care system $210 million annually. We believe that pseudocellulitis would be best evaluated by inpatient dermatology teams, thereby avoiding costly dermatologic consultations, at an average rate of $138.89.⁶

Morbilliform drug eruptions are among the most common skin conditions seen in the hospital; approximately 95% of cases are an uncomplicated reaction to a medication or virus. Data show that many of these consultations might be unnecessary.⁷

Our institution (Hackensack University Medical Center, New Jersey) is a tertiary hospital that also is connected with a major cancer center. Given this connection, skin eruptions due to chemotherapy and radiation are common. The treatment of drug eruptions, graft-vs-host disease, and other oncologic or drug-related eruptions should be within the scope of practice of our hospitalists, but these cases frequently involve dermatologic consultation.

We constructed a consultation flowchart (Figure) to help guide the triage of patients in need of dermatologic evaluation by inpatient teams and possibly to avoid unnecessary consultation fees. The manner in which this—or any flowchart or teaching aid—is conveyed to hospital personnel is critical so that these tools are not perceived as patronizing or confrontational. In our flowchart, we list emergent dermatologic conditions that we believe are appropriate for dermatology consultation including erythrodermic psoriasis, bullous pemphigoid flare, and Stevens-Johnson syndrome/toxic epidermal necrolysis.

We believe that the flowchart can educate inpatient medical teams about appropriate dermatology consultation. Use of the flowchart also may decrease unnecessary consultations, which ultimately will lower health care spending overall.

There are limited clinical data concerning inpatient and emergency department (ED) dermatologic consultations. The indications for these consultations vary widely, but in one study (N=271), it was found that 21% of inpatient consultations were for contact dermatitis and 10% were for drug eruptions.¹ In the same study, 77% of patients who required a dermatology consultation eventually were given a different diagnosis or change in treatment after consultation. For example, of all consultations for suspected cellulitis, only 10% were confirmed after dermatology evaluation.¹

Hospitalists and emergency physicians continue to struggle with the assessment of dermatologic conditions, often consulting dermatology whenever a patient has a “rash” or skin concern. Dermatology is still not emphasized in medical education and often is taught to most medical students in an abbreviated fashion, which results in physicians feeling ill-equipped to deal with any dermatologic condition—either mundane or potentially life-threatening. A study in 2016 showed that a monthly lecture series given to hospitalists over the course of 5 years did not improve diagnostic accuracy in patients who were admitted with skin manifestations.² This further shows that there is a need for dermatologic experts in the hospital.

We need to develop better guidelines for physicians in the ED and on inpatient units to guide them on appropriate use of dermatologic consultation outside the ambulatory office and the clinic. A 2013 study showed that patients often were discharged immediately after a dermatologic consultation, furthering our hypothesis that many inpatient consultations can be delayed until after discharge.³

In an era in which medical costs are soaring and there is constant surveillance for ways to reduce costs without impairing quality of care, limiting unnecessary specialty consultations should be embraced. In 2009, $1.8 billion in Medicare claims was paid for dermatology-related admissions.³ A substantial savings to Medicare consulting fees for certain diagnoses, such as cellulitis or contact dermatitis, could be realized if patients were referred for outpatient assessment and treatment. In a study of 271 consultations, 54 patients also had a skin biopsy, which further increases dollars spent on inpatient care and is (usually) something that can be performed in the outpatient setting.¹ In another study, the more common recommended treatments were topical corticosteroids and supportive educational measures for patients and hospital staff,³ which further substantiates that most dermatology consultations are not truly emergent and can wait for outpatient consultation.

In addition, we are dealing with the COVID-19 pandemic in our hospitals and EDs. Many physicians, including dermatologists, would prefer to avoid unnecessary exposure to SARS-CoV-2 on inpatient units and in the ED. It certainly would be preferable to require consultants to come in to evaluate patients only when they truly need to be seen while in the hospital.

There also is limited dermatology training in other specialties, and the dermatology team can help fill this gap with educational programs and one-on-one teaching. Hospital teams have signaled this need, but there has been limited success with multiple teaching opportunities.⁴

We believe that this need for inpatient dermatology services can be filled with the newer subspecialty of hospital dermatology, which is not commonly present at most hospitals; a reason why the subspecialty has not been more popular is that there are few available data in the form of randomized clinical trials that can guide inpatient dermatologists with the care of rare hospital skin diseases.⁵ Having a dermatologic hospitalist available might allow for patients to be seen more readily, which ultimately will save lives and health care dollars and would increase real-time teaching and education for house staff, nursing, and attendings at the bedside.

In a 2018 article,⁶ it was postulated that quicker diagnosis of pseudocellulitis and initiation of antibiotics to treat this condition would save the US health care system $210 million annually. We believe that pseudocellulitis would be best evaluated by inpatient dermatology teams, thereby avoiding costly dermatologic consultations, at an average rate of $138.89.⁶

Morbilliform drug eruptions are among the most common skin conditions seen in the hospital; approximately 95% of cases are an uncomplicated reaction to a medication or virus. Data show that many of these consultations might be unnecessary.⁷

Our institution (Hackensack University Medical Center, New Jersey) is a tertiary hospital that also is connected with a major cancer center. Given this connection, skin eruptions due to chemotherapy and radiation are common. The treatment of drug eruptions, graft-vs-host disease, and other oncologic or drug-related eruptions should be within the scope of practice of our hospitalists, but these cases frequently involve dermatologic consultation.

We constructed a consultation flowchart (Figure) to help guide the triage of patients in need of dermatologic evaluation by inpatient teams and possibly to avoid unnecessary consultation fees. The manner in which this—or any flowchart or teaching aid—is conveyed to hospital personnel is critical so that these tools are not perceived as patronizing or confrontational. In our flowchart, we list emergent dermatologic conditions that we believe are appropriate for dermatology consultation including erythrodermic psoriasis, bullous pemphigoid flare, and Stevens-Johnson syndrome/toxic epidermal necrolysis.

We believe that the flowchart can educate inpatient medical teams about appropriate dermatology consultation. Use of the flowchart also may decrease unnecessary consultations, which ultimately will lower health care spending overall.

Edema blisters are a common but often underreported entity most commonly seen on the lower extremities in the setting of acute edema. ¹ Reported risk factors and associations include chronic venous insufficiency, congestive heart failure, hereditary angioedema, and medications (eg, amlodipine). ^1,2 We report a newly described variant that we have termed anasarca-induced desquamation in which a patient sloughed the entire cutaneous surface of the body after gaining almost 40 pounds over 5 days.

Case Report

A 50-year-old man without a home was found minimally responsive in a yard. His core body temperature was 25.5 °C. He was profoundly acidotic (pH, <6.733 [reference range, 7.35–7.45]; lactic acid, 20.5 mmol/L [reference range, 0.5–2.2 mmol/L]) at admission. His medical history was notable for diabetes mellitus, hypertension, alcohol abuse, and pulmonary embolism. The patient was resuscitated with rewarming and intravenous fluids in the setting of acute renal insufficiency. By day 5 of the hospital stay, he had a net positive intake of 21.8 L and an 18-kg (39.7-lb) weight gain.

Dermatology was consulted for skin sloughing. Physical examination revealed nonpainful desquamation of the vermilion lip, periorbital skin, right shoulder, and hips without notable mucosal changes. Two 4-mm punch biopsies of the shoulder revealed an intracorneal split with desquamation of the stratum corneum and a mild dermal lymphocytic infiltrate, consistent with exfoliation secondary to edema or staphylococcal scalded skin syndrome (Figure 1). No staphylococcal growth was noted on blood, urine, nasal, wound, and ocular cultures throughout the hospital stay.

As the patient’s anasarca improved with diuretics and continuous renal replacement therapy, the entire cutaneous surface—head to toe—underwent desquamation, including the palms and soles. He was managed with supportive skin care. The anasarca healed completely with residual hypopigmentation (Figures 2 and 3).

Comment

Anasarca-induced desquamation represents a more diffuse form of a known entity: edema blisters. Occurring most commonly in the setting of acute exacerbation of chronic venous insufficiency, edema blisters can mimic other vesiculobullous conditions, such as bullous pemphigoid and herpes zoster.³

Pathogenesis of Edema Blisters—Edema develops in the skin when the capillary filtration rate, determined by the hydrostatic and oncotic pressures of the capillaries and interstitium, exceeds venous and lymphatic drainage. The appearance of edema blisters in the acute setting likely is related to the speed at which edema develops in skin.¹ Although edema blisters often are described as tense, there is a paucity of histologic data at the anatomical level of split in the skin.In our patient, desquamation was within the stratum corneum and likely multifactorial. His weight gain of nearly 40 lb, the result of intravenous instillation of fluids and low urine output, was undeniably a contributing factor. The anasarca was aggravated by hypoalbuminemia (2.1 g/dL) in the setting of known liver disease. Other possible contributing factors were hypotension, which required vasopressor therapy that led to hypoperfusion of the skin, and treatment of hypothermia, with resulting reactive vasodilation and capillary leak.

Management—Treatment of acute edema blisters is focused on the underlying cause of the edema. In a study of 13 patients with edema blisters, all had blisters on the legs that resolved with treatment, such as diuretics or compression therapy.¹

Anasarca-induced desquamation is an inherently benign condition that mimics potentially fatal disorders, such as Stevens-Johnson syndrome, staphylococcal scalded skin syndrome, and toxic shock syndrome. Therefore, patients presenting with diffuse superficial desquamation should be assessed for the mucosal changes of Stevens-Johnson syndrome and a history of acute edema in the affected areas to avoid potentially harmful empiric treatments, such as corticosteroids and intravenous antibiotics.

Conclusion

Anasarca-induced desquamation represents a more diffuse form of edema blisters. This desquamation can mimic a potentially fatal rash, such as Stevens-Johnson syndrome and staphylococcal scalded skin syndrome.

Edema blisters are a common but often underreported entity most commonly seen on the lower extremities in the setting of acute edema. ¹ Reported risk factors and associations include chronic venous insufficiency, congestive heart failure, hereditary angioedema, and medications (eg, amlodipine). ^1,2 We report a newly described variant that we have termed anasarca-induced desquamation in which a patient sloughed the entire cutaneous surface of the body after gaining almost 40 pounds over 5 days.

Case Report

A 50-year-old man without a home was found minimally responsive in a yard. His core body temperature was 25.5 °C. He was profoundly acidotic (pH, <6.733 [reference range, 7.35–7.45]; lactic acid, 20.5 mmol/L [reference range, 0.5–2.2 mmol/L]) at admission. His medical history was notable for diabetes mellitus, hypertension, alcohol abuse, and pulmonary embolism. The patient was resuscitated with rewarming and intravenous fluids in the setting of acute renal insufficiency. By day 5 of the hospital stay, he had a net positive intake of 21.8 L and an 18-kg (39.7-lb) weight gain.

Dermatology was consulted for skin sloughing. Physical examination revealed nonpainful desquamation of the vermilion lip, periorbital skin, right shoulder, and hips without notable mucosal changes. Two 4-mm punch biopsies of the shoulder revealed an intracorneal split with desquamation of the stratum corneum and a mild dermal lymphocytic infiltrate, consistent with exfoliation secondary to edema or staphylococcal scalded skin syndrome (Figure 1). No staphylococcal growth was noted on blood, urine, nasal, wound, and ocular cultures throughout the hospital stay.

As the patient’s anasarca improved with diuretics and continuous renal replacement therapy, the entire cutaneous surface—head to toe—underwent desquamation, including the palms and soles. He was managed with supportive skin care. The anasarca healed completely with residual hypopigmentation (Figures 2 and 3).

Comment

Anasarca-induced desquamation represents a more diffuse form of a known entity: edema blisters. Occurring most commonly in the setting of acute exacerbation of chronic venous insufficiency, edema blisters can mimic other vesiculobullous conditions, such as bullous pemphigoid and herpes zoster.³

Pathogenesis of Edema Blisters—Edema develops in the skin when the capillary filtration rate, determined by the hydrostatic and oncotic pressures of the capillaries and interstitium, exceeds venous and lymphatic drainage. The appearance of edema blisters in the acute setting likely is related to the speed at which edema develops in skin.¹ Although edema blisters often are described as tense, there is a paucity of histologic data at the anatomical level of split in the skin.In our patient, desquamation was within the stratum corneum and likely multifactorial. His weight gain of nearly 40 lb, the result of intravenous instillation of fluids and low urine output, was undeniably a contributing factor. The anasarca was aggravated by hypoalbuminemia (2.1 g/dL) in the setting of known liver disease. Other possible contributing factors were hypotension, which required vasopressor therapy that led to hypoperfusion of the skin, and treatment of hypothermia, with resulting reactive vasodilation and capillary leak.

Management—Treatment of acute edema blisters is focused on the underlying cause of the edema. In a study of 13 patients with edema blisters, all had blisters on the legs that resolved with treatment, such as diuretics or compression therapy.¹

Anasarca-induced desquamation is an inherently benign condition that mimics potentially fatal disorders, such as Stevens-Johnson syndrome, staphylococcal scalded skin syndrome, and toxic shock syndrome. Therefore, patients presenting with diffuse superficial desquamation should be assessed for the mucosal changes of Stevens-Johnson syndrome and a history of acute edema in the affected areas to avoid potentially harmful empiric treatments, such as corticosteroids and intravenous antibiotics.

Conclusion

Anasarca-induced desquamation represents a more diffuse form of edema blisters. This desquamation can mimic a potentially fatal rash, such as Stevens-Johnson syndrome and staphylococcal scalded skin syndrome.

Edema blisters are a common but often underreported entity most commonly seen on the lower extremities in the setting of acute edema. ¹ Reported risk factors and associations include chronic venous insufficiency, congestive heart failure, hereditary angioedema, and medications (eg, amlodipine). ^1,2 We report a newly described variant that we have termed anasarca-induced desquamation in which a patient sloughed the entire cutaneous surface of the body after gaining almost 40 pounds over 5 days.

Case Report

A 50-year-old man without a home was found minimally responsive in a yard. His core body temperature was 25.5 °C. He was profoundly acidotic (pH, <6.733 [reference range, 7.35–7.45]; lactic acid, 20.5 mmol/L [reference range, 0.5–2.2 mmol/L]) at admission. His medical history was notable for diabetes mellitus, hypertension, alcohol abuse, and pulmonary embolism. The patient was resuscitated with rewarming and intravenous fluids in the setting of acute renal insufficiency. By day 5 of the hospital stay, he had a net positive intake of 21.8 L and an 18-kg (39.7-lb) weight gain.

Dermatology was consulted for skin sloughing. Physical examination revealed nonpainful desquamation of the vermilion lip, periorbital skin, right shoulder, and hips without notable mucosal changes. Two 4-mm punch biopsies of the shoulder revealed an intracorneal split with desquamation of the stratum corneum and a mild dermal lymphocytic infiltrate, consistent with exfoliation secondary to edema or staphylococcal scalded skin syndrome (Figure 1). No staphylococcal growth was noted on blood, urine, nasal, wound, and ocular cultures throughout the hospital stay.

As the patient’s anasarca improved with diuretics and continuous renal replacement therapy, the entire cutaneous surface—head to toe—underwent desquamation, including the palms and soles. He was managed with supportive skin care. The anasarca healed completely with residual hypopigmentation (Figures 2 and 3).

Comment

Anasarca-induced desquamation represents a more diffuse form of a known entity: edema blisters. Occurring most commonly in the setting of acute exacerbation of chronic venous insufficiency, edema blisters can mimic other vesiculobullous conditions, such as bullous pemphigoid and herpes zoster.³

Pathogenesis of Edema Blisters—Edema develops in the skin when the capillary filtration rate, determined by the hydrostatic and oncotic pressures of the capillaries and interstitium, exceeds venous and lymphatic drainage. The appearance of edema blisters in the acute setting likely is related to the speed at which edema develops in skin.¹ Although edema blisters often are described as tense, there is a paucity of histologic data at the anatomical level of split in the skin.In our patient, desquamation was within the stratum corneum and likely multifactorial. His weight gain of nearly 40 lb, the result of intravenous instillation of fluids and low urine output, was undeniably a contributing factor. The anasarca was aggravated by hypoalbuminemia (2.1 g/dL) in the setting of known liver disease. Other possible contributing factors were hypotension, which required vasopressor therapy that led to hypoperfusion of the skin, and treatment of hypothermia, with resulting reactive vasodilation and capillary leak.

Management—Treatment of acute edema blisters is focused on the underlying cause of the edema. In a study of 13 patients with edema blisters, all had blisters on the legs that resolved with treatment, such as diuretics or compression therapy.¹

Anasarca-induced desquamation is an inherently benign condition that mimics potentially fatal disorders, such as Stevens-Johnson syndrome, staphylococcal scalded skin syndrome, and toxic shock syndrome. Therefore, patients presenting with diffuse superficial desquamation should be assessed for the mucosal changes of Stevens-Johnson syndrome and a history of acute edema in the affected areas to avoid potentially harmful empiric treatments, such as corticosteroids and intravenous antibiotics.

Conclusion

Anasarca-induced desquamation represents a more diffuse form of edema blisters. This desquamation can mimic a potentially fatal rash, such as Stevens-Johnson syndrome and staphylococcal scalded skin syndrome.

Case Report

A 58-year-old woman presented to the dermatology office with a widespread pruritic eruption of 3 days’ duration that started in the groin and spread to the rest of the body. No treatments had been attempted. She had no notable medical history, and she denied any recent illness, change in personal care products, or new medications or supplements. She reported a camping trip 2 weeks prior to presentation on the east end of Long Island, New York. She later learned that others on the same trip developed a similar, albeit less widespread, eruption.

Physical examination revealed clear vesicles on the arms, legs, trunk, and pubic area (Figure 1). Dermoscopy revealed a small lone star tick larva in the center of one of the vesicles (Figure 2). The type of tick larva was identified using resources from the Centers for Disease Control and Prevention (Figure 3).¹ Careful inspection revealed dark marks on various vesicles, mostly in the perineum, yielding nearly 20 larvae, which were removed with forceps. The patient was counseled to cover herself in petrolatum for 2 to 3 hours with the hope of smothering any remaining tick larvae. She was given triamcinolone cream and was encouraged to take a nonsedating antihistamine for itch. The patient was seen back in clinic 2 weeks later and the eruption had resolved.

Comment

Spread of Tick-Borne Disease—Ticks and tick-borne disease are increasing major health concerns for humans, domesticated animals, and livestock. Reported cases of bacterial and protozoan tick-borne disease doubled in the United States between 2004 and 2016. Ninety percent of the nearly 60,000 cases of nationally notifiable vector-borne diseases reported in 2017 were linked to ticks.² Geographic ranges of multiple tick species continue to expand, which is thought to be secondary to rising global temperatures, ecologic changes, reforestation, and increases in commerce and travel (Figure 4).³ Not only have warming temperatures contributed to geographic range expansion, they also may extend ticks’ active season. The lone star tick (Amblyomma americanum) is widely distributed throughout much of the eastern United States.⁴ The range of A americanum has expanded north in recent years from its prior core range in the southeastern United States.² One study found that from 2006 to 2016, the vector tick species most commonly collected from humans and submitted to a tick surveillance system in New Jersey shifted from Ixodes scapularis to A americanum.⁵

Bites by Amblyomma Ticks—As with most hard ticks, the life cycle of A americanum lasts 2 years and includes the egg, the 6-legged larva or “seed tick,” the 8-legged immature nymph, and the 8-legged reproductively mature adult (Figure 3). Amblyomma americanum can lay several thousand eggs.² Because our patient had numerous bites, it is plausible that she came into contact with a nest of newly hatched tick larvae. Morphogenesis from larva to nymph, then nymph to adult, requires a blood meal.^6,7 The larvae emerge from eggs deposited on the ground and then crawl up low vegetation where they can easily attach to passing hosts. The tick clings to hair or clothing and waits until the host is at rest before moving to a favorable location and then bites.⁸ When attaching, ticks inject an anesthetic akin to lidocaine, making the bite painless. A tick may spend up to 24 hours on the host prior to biting and then feed for 2 hours to 7 days before releasing.⁹ For the majority of tick-borne illnesses, the tick must remain attached for 24 to 48 hours before disease is transmitted.¹⁰

All stages of Amblyomma, excluding the egg, are capable of transmitting disease.^8,11Amblyomma americanum is called the lone star tick because of the prominent white dot on the back of the adult female. It will feed on small or large mammals during any stage of its life cycle. It is known to transmit Ehrlichia chaffeensis and Ehrlichia ewingii, which cause human ehrlichiosis, and Francisella tularensis, which causes tularemia, Heartland virus, Bourbon virus, and Southern tick-associated rash illness. Delayed anaphylaxis to ingestion of red meat has been attributed to the bite of A americanum. Amblyomma americanum ticks are not known to transmit Lyme disease. The Centers for Disease Control and Prevention does not recommend prophylactic treatment to prevent ehrlichiosis.¹² Tularemia prophylaxis is only recommended in cases of laboratory exposure to infectious materials. Doxycycline prophylaxis is only recommended if the tick is identified as an adult or nymphal I scapularis.¹²

Even when the ticks do not transmit disease, tick bites can cause impressive local reactions. Uncomplicated bites can be painful and leave a puncture wound that can take 1 to 2 weeks to heal.¹³ Rarely, bites can cause a delayed hypersensitivity reaction including fever, pruritus, and urticaria. Granulomas can develop if a tick is improperly removed.⁹ Other reports describe prurigo lesions, skin hemorrhage, papular urticaria, diffuse papules, vesicles and bullae, necrotic ulcers, and patchy alopecia.^14,15 A 2015 systematic controlled study of human bite reactions from A americanum demonstrated the development of itchy erythematous papules and vesicles within 48 hours of larval tick attachment to research participants. The study found tissue damage from A americanum mouthparts, and degranulating mast cells may be evident in as little as 15 minutes.¹⁶ The severity of individual skin reaction is hypothesized to depend on several variables, such as the duration of feeding, size of mouthparts, type of tick secretions, changes in secretions during feeding, and prior exposures of the host.¹⁴

Tick Removal—If patients present to clinic with ticks attached, removal can be challenging. Removal recommendations call for use of blunt forceps or tweezers. Ticks should be grasped near the skin with consistent pressure, and the tick should be pulled straight out, perpendicular to the skin. Twisting motions can cause the head to separate from the body and remain in the bite wound. Immediately following removal, the area should be cleansed with a disinfectant.^10,17 After the tick is removed, some studies recommend storing the tick at −20 °C; should the patient develop disease, the tick could be sent for evaluation.^6,17 If there is no clinical or serologic evidence of infection, testing for the presence of antibodies against tick-borne bacteria at presentation and at 3 and 6 weeks is not recommended due to low sensitivity, low positive predictive value, and cost. Clinicians must only observe and treat if disease occurs.¹⁷

Prevention of Tick Bites—Tick bites are best prevented by avoiding tick-infested areas; when these areas are unavoidable, tick bites may be prevented by wearing long pants with the pant legs tucked into boots. In addition, applying topical DEET (N,N-diethyl-m-toluamide) repellent to exposed skin and treating clothing with permethrin can be helpful.¹⁷ When used alone, DEET provides greater than 90% protection for up to 2.7 hours against A americanum.¹⁸ Permethrin-treated clothing alone is 79% to 100% effective at killing A americanum ticks or disabling them for several hours.¹⁹

Conclusion

Tick-borne illness is an increasingly important cause of human infectious disease. In addition to their role as a disease vector, ticks can produce primary skin disorders. This case posed a diagnostic challenge because of the unusually large number and wide distribution of bites as well as the subsequent vesicular reaction that ensued. It is important to keep tick larvae or adult tick bites in the differential when evaluating a patient to expedite tick removal and begin clinical monitoring. Recognition of A americanum larvae as a potential cause of pruritic papules may be helpful in similar cases. In addition, it is important for dermatologists to be aware of the tick species in their area.

Case Report

A 58-year-old woman presented to the dermatology office with a widespread pruritic eruption of 3 days’ duration that started in the groin and spread to the rest of the body. No treatments had been attempted. She had no notable medical history, and she denied any recent illness, change in personal care products, or new medications or supplements. She reported a camping trip 2 weeks prior to presentation on the east end of Long Island, New York. She later learned that others on the same trip developed a similar, albeit less widespread, eruption.

Physical examination revealed clear vesicles on the arms, legs, trunk, and pubic area (Figure 1). Dermoscopy revealed a small lone star tick larva in the center of one of the vesicles (Figure 2). The type of tick larva was identified using resources from the Centers for Disease Control and Prevention (Figure 3).¹ Careful inspection revealed dark marks on various vesicles, mostly in the perineum, yielding nearly 20 larvae, which were removed with forceps. The patient was counseled to cover herself in petrolatum for 2 to 3 hours with the hope of smothering any remaining tick larvae. She was given triamcinolone cream and was encouraged to take a nonsedating antihistamine for itch. The patient was seen back in clinic 2 weeks later and the eruption had resolved.

Comment

Spread of Tick-Borne Disease—Ticks and tick-borne disease are increasing major health concerns for humans, domesticated animals, and livestock. Reported cases of bacterial and protozoan tick-borne disease doubled in the United States between 2004 and 2016. Ninety percent of the nearly 60,000 cases of nationally notifiable vector-borne diseases reported in 2017 were linked to ticks.² Geographic ranges of multiple tick species continue to expand, which is thought to be secondary to rising global temperatures, ecologic changes, reforestation, and increases in commerce and travel (Figure 4).³ Not only have warming temperatures contributed to geographic range expansion, they also may extend ticks’ active season. The lone star tick (Amblyomma americanum) is widely distributed throughout much of the eastern United States.⁴ The range of A americanum has expanded north in recent years from its prior core range in the southeastern United States.² One study found that from 2006 to 2016, the vector tick species most commonly collected from humans and submitted to a tick surveillance system in New Jersey shifted from Ixodes scapularis to A americanum.⁵

Bites by Amblyomma Ticks—As with most hard ticks, the life cycle of A americanum lasts 2 years and includes the egg, the 6-legged larva or “seed tick,” the 8-legged immature nymph, and the 8-legged reproductively mature adult (Figure 3). Amblyomma americanum can lay several thousand eggs.² Because our patient had numerous bites, it is plausible that she came into contact with a nest of newly hatched tick larvae. Morphogenesis from larva to nymph, then nymph to adult, requires a blood meal.^6,7 The larvae emerge from eggs deposited on the ground and then crawl up low vegetation where they can easily attach to passing hosts. The tick clings to hair or clothing and waits until the host is at rest before moving to a favorable location and then bites.⁸ When attaching, ticks inject an anesthetic akin to lidocaine, making the bite painless. A tick may spend up to 24 hours on the host prior to biting and then feed for 2 hours to 7 days before releasing.⁹ For the majority of tick-borne illnesses, the tick must remain attached for 24 to 48 hours before disease is transmitted.¹⁰

All stages of Amblyomma, excluding the egg, are capable of transmitting disease.^8,11Amblyomma americanum is called the lone star tick because of the prominent white dot on the back of the adult female. It will feed on small or large mammals during any stage of its life cycle. It is known to transmit Ehrlichia chaffeensis and Ehrlichia ewingii, which cause human ehrlichiosis, and Francisella tularensis, which causes tularemia, Heartland virus, Bourbon virus, and Southern tick-associated rash illness. Delayed anaphylaxis to ingestion of red meat has been attributed to the bite of A americanum. Amblyomma americanum ticks are not known to transmit Lyme disease. The Centers for Disease Control and Prevention does not recommend prophylactic treatment to prevent ehrlichiosis.¹² Tularemia prophylaxis is only recommended in cases of laboratory exposure to infectious materials. Doxycycline prophylaxis is only recommended if the tick is identified as an adult or nymphal I scapularis.¹²

Even when the ticks do not transmit disease, tick bites can cause impressive local reactions. Uncomplicated bites can be painful and leave a puncture wound that can take 1 to 2 weeks to heal.¹³ Rarely, bites can cause a delayed hypersensitivity reaction including fever, pruritus, and urticaria. Granulomas can develop if a tick is improperly removed.⁹ Other reports describe prurigo lesions, skin hemorrhage, papular urticaria, diffuse papules, vesicles and bullae, necrotic ulcers, and patchy alopecia.^14,15 A 2015 systematic controlled study of human bite reactions from A americanum demonstrated the development of itchy erythematous papules and vesicles within 48 hours of larval tick attachment to research participants. The study found tissue damage from A americanum mouthparts, and degranulating mast cells may be evident in as little as 15 minutes.¹⁶ The severity of individual skin reaction is hypothesized to depend on several variables, such as the duration of feeding, size of mouthparts, type of tick secretions, changes in secretions during feeding, and prior exposures of the host.¹⁴

Tick Removal—If patients present to clinic with ticks attached, removal can be challenging. Removal recommendations call for use of blunt forceps or tweezers. Ticks should be grasped near the skin with consistent pressure, and the tick should be pulled straight out, perpendicular to the skin. Twisting motions can cause the head to separate from the body and remain in the bite wound. Immediately following removal, the area should be cleansed with a disinfectant.^10,17 After the tick is removed, some studies recommend storing the tick at −20 °C; should the patient develop disease, the tick could be sent for evaluation.^6,17 If there is no clinical or serologic evidence of infection, testing for the presence of antibodies against tick-borne bacteria at presentation and at 3 and 6 weeks is not recommended due to low sensitivity, low positive predictive value, and cost. Clinicians must only observe and treat if disease occurs.¹⁷

Prevention of Tick Bites—Tick bites are best prevented by avoiding tick-infested areas; when these areas are unavoidable, tick bites may be prevented by wearing long pants with the pant legs tucked into boots. In addition, applying topical DEET (N,N-diethyl-m-toluamide) repellent to exposed skin and treating clothing with permethrin can be helpful.¹⁷ When used alone, DEET provides greater than 90% protection for up to 2.7 hours against A americanum.¹⁸ Permethrin-treated clothing alone is 79% to 100% effective at killing A americanum ticks or disabling them for several hours.¹⁹

Conclusion

Tick-borne illness is an increasingly important cause of human infectious disease. In addition to their role as a disease vector, ticks can produce primary skin disorders. This case posed a diagnostic challenge because of the unusually large number and wide distribution of bites as well as the subsequent vesicular reaction that ensued. It is important to keep tick larvae or adult tick bites in the differential when evaluating a patient to expedite tick removal and begin clinical monitoring. Recognition of A americanum larvae as a potential cause of pruritic papules may be helpful in similar cases. In addition, it is important for dermatologists to be aware of the tick species in their area.

Case Report

A 58-year-old woman presented to the dermatology office with a widespread pruritic eruption of 3 days’ duration that started in the groin and spread to the rest of the body. No treatments had been attempted. She had no notable medical history, and she denied any recent illness, change in personal care products, or new medications or supplements. She reported a camping trip 2 weeks prior to presentation on the east end of Long Island, New York. She later learned that others on the same trip developed a similar, albeit less widespread, eruption.

Physical examination revealed clear vesicles on the arms, legs, trunk, and pubic area (Figure 1). Dermoscopy revealed a small lone star tick larva in the center of one of the vesicles (Figure 2). The type of tick larva was identified using resources from the Centers for Disease Control and Prevention (Figure 3).¹ Careful inspection revealed dark marks on various vesicles, mostly in the perineum, yielding nearly 20 larvae, which were removed with forceps. The patient was counseled to cover herself in petrolatum for 2 to 3 hours with the hope of smothering any remaining tick larvae. She was given triamcinolone cream and was encouraged to take a nonsedating antihistamine for itch. The patient was seen back in clinic 2 weeks later and the eruption had resolved.

Comment

Spread of Tick-Borne Disease—Ticks and tick-borne disease are increasing major health concerns for humans, domesticated animals, and livestock. Reported cases of bacterial and protozoan tick-borne disease doubled in the United States between 2004 and 2016. Ninety percent of the nearly 60,000 cases of nationally notifiable vector-borne diseases reported in 2017 were linked to ticks.² Geographic ranges of multiple tick species continue to expand, which is thought to be secondary to rising global temperatures, ecologic changes, reforestation, and increases in commerce and travel (Figure 4).³ Not only have warming temperatures contributed to geographic range expansion, they also may extend ticks’ active season. The lone star tick (Amblyomma americanum) is widely distributed throughout much of the eastern United States.⁴ The range of A americanum has expanded north in recent years from its prior core range in the southeastern United States.² One study found that from 2006 to 2016, the vector tick species most commonly collected from humans and submitted to a tick surveillance system in New Jersey shifted from Ixodes scapularis to A americanum.⁵

Bites by Amblyomma Ticks—As with most hard ticks, the life cycle of A americanum lasts 2 years and includes the egg, the 6-legged larva or “seed tick,” the 8-legged immature nymph, and the 8-legged reproductively mature adult (Figure 3). Amblyomma americanum can lay several thousand eggs.² Because our patient had numerous bites, it is plausible that she came into contact with a nest of newly hatched tick larvae. Morphogenesis from larva to nymph, then nymph to adult, requires a blood meal.^6,7 The larvae emerge from eggs deposited on the ground and then crawl up low vegetation where they can easily attach to passing hosts. The tick clings to hair or clothing and waits until the host is at rest before moving to a favorable location and then bites.⁸ When attaching, ticks inject an anesthetic akin to lidocaine, making the bite painless. A tick may spend up to 24 hours on the host prior to biting and then feed for 2 hours to 7 days before releasing.⁹ For the majority of tick-borne illnesses, the tick must remain attached for 24 to 48 hours before disease is transmitted.¹⁰

All stages of Amblyomma, excluding the egg, are capable of transmitting disease.^8,11Amblyomma americanum is called the lone star tick because of the prominent white dot on the back of the adult female. It will feed on small or large mammals during any stage of its life cycle. It is known to transmit Ehrlichia chaffeensis and Ehrlichia ewingii, which cause human ehrlichiosis, and Francisella tularensis, which causes tularemia, Heartland virus, Bourbon virus, and Southern tick-associated rash illness. Delayed anaphylaxis to ingestion of red meat has been attributed to the bite of A americanum. Amblyomma americanum ticks are not known to transmit Lyme disease. The Centers for Disease Control and Prevention does not recommend prophylactic treatment to prevent ehrlichiosis.¹² Tularemia prophylaxis is only recommended in cases of laboratory exposure to infectious materials. Doxycycline prophylaxis is only recommended if the tick is identified as an adult or nymphal I scapularis.¹²

Even when the ticks do not transmit disease, tick bites can cause impressive local reactions. Uncomplicated bites can be painful and leave a puncture wound that can take 1 to 2 weeks to heal.¹³ Rarely, bites can cause a delayed hypersensitivity reaction including fever, pruritus, and urticaria. Granulomas can develop if a tick is improperly removed.⁹ Other reports describe prurigo lesions, skin hemorrhage, papular urticaria, diffuse papules, vesicles and bullae, necrotic ulcers, and patchy alopecia.^14,15 A 2015 systematic controlled study of human bite reactions from A americanum demonstrated the development of itchy erythematous papules and vesicles within 48 hours of larval tick attachment to research participants. The study found tissue damage from A americanum mouthparts, and degranulating mast cells may be evident in as little as 15 minutes.¹⁶ The severity of individual skin reaction is hypothesized to depend on several variables, such as the duration of feeding, size of mouthparts, type of tick secretions, changes in secretions during feeding, and prior exposures of the host.¹⁴

Tick Removal—If patients present to clinic with ticks attached, removal can be challenging. Removal recommendations call for use of blunt forceps or tweezers. Ticks should be grasped near the skin with consistent pressure, and the tick should be pulled straight out, perpendicular to the skin. Twisting motions can cause the head to separate from the body and remain in the bite wound. Immediately following removal, the area should be cleansed with a disinfectant.^10,17 After the tick is removed, some studies recommend storing the tick at −20 °C; should the patient develop disease, the tick could be sent for evaluation.^6,17 If there is no clinical or serologic evidence of infection, testing for the presence of antibodies against tick-borne bacteria at presentation and at 3 and 6 weeks is not recommended due to low sensitivity, low positive predictive value, and cost. Clinicians must only observe and treat if disease occurs.¹⁷

Prevention of Tick Bites—Tick bites are best prevented by avoiding tick-infested areas; when these areas are unavoidable, tick bites may be prevented by wearing long pants with the pant legs tucked into boots. In addition, applying topical DEET (N,N-diethyl-m-toluamide) repellent to exposed skin and treating clothing with permethrin can be helpful.¹⁷ When used alone, DEET provides greater than 90% protection for up to 2.7 hours against A americanum.¹⁸ Permethrin-treated clothing alone is 79% to 100% effective at killing A americanum ticks or disabling them for several hours.¹⁹

Conclusion

Tick-borne illness is an increasingly important cause of human infectious disease. In addition to their role as a disease vector, ticks can produce primary skin disorders. This case posed a diagnostic challenge because of the unusually large number and wide distribution of bites as well as the subsequent vesicular reaction that ensued. It is important to keep tick larvae or adult tick bites in the differential when evaluating a patient to expedite tick removal and begin clinical monitoring. Recognition of A americanum larvae as a potential cause of pruritic papules may be helpful in similar cases. In addition, it is important for dermatologists to be aware of the tick species in their area.

BOSTON – The American Contact Dermatitis Society (ACDS) has selected aluminum as the Allergen of the Year for 2022. Aluminum salts, which are the major cause of allergic reactions, are “ubiquitous,” Donald Belsito, MD, professor of dermatology at Columbia University, New York, said at the annual meeting of the American Contact Dermatitis Society.

These salts can be found in sunscreen, cosmetics, dental restorations, and food, to name a few, though the most commonly identified reactions are from aluminum hydroxide, which can be found in some vaccines or preparations for allergen-specific immunotherapy. “It’s the aluminum hydroxide that seems to be more allergenic than other aluminum salts,” Dr. Belsito said in an interview.

“It’s not a dangerous allergy; It’s not a threat,” he said, “but it’s something that dermatologists need to be aware of.”

These reactions normally present as itchy nodules that can last for months and even years, like some reactions from patch testing. “We’re not talking about a vaccine allergy in such a way where people are getting anaphylaxis,” JiaDe Yu, MD, a pediatric dermatologist specializing in allergic contact dermatitis at Massachusetts General Hospital, Boston, said in an interview. “An itchy rash is what we tend to see.”

There have also been occasional reports of atopic dermatitis from aluminum in antiperspirants, astringents, as well as from the metallic aluminum.

Dr. Yu noted that aluminum allergies are not thought to be very common, but the overall prevalence is not known. Studies do suggest, however, that the allergy may be more prevalent in children. In one recent study in Sweden, 5% of children and 0.9% of adults who underwent patch testing had an aluminum contact allergy.

Recommendations for testing

Aluminum is not included in baseline patch testing in the United States, though a recent report about the allergen in the journal Dermatitis argued for its inclusion for pediatric patch testing. Both Dr. Belsito and Dr. Yu agreed that the best approach is to do targeted testing. “If there is a suspicion for it, absolutely test for it,” Dr. Yu said, but if a patient comes in with something like eyelid dermatitis or a rash after a hair care appointment, an aluminum allergy is not very likely.

Because aluminum is also present in Finn Chambers for patch testing, Dr. Belsito advised using plastic chambers in people suspected of having an aluminum allergy. He now uses only plastic chambers in children, he said, as some patients have had reactions to the Finn Chambers even if they have no history of reactions to vaccines or other aluminum-containing products.

While aluminum chloride hexahydrate (ACH) 2% in petrolatum is the commercially available preparation in patch testing, a preparation with ACH 10% is more sensitive, Dr. Belsito said. If a physician strongly suspects an aluminum allergy in a patient but the test with the ACH 2% is negative, he or she should then try a 10% solution, he noted, adding that 7-day readings are also necessary to maximize accuracy.

Vaccine safety

One of the concerns about naming aluminum as the allergen of the year is the potential to cause anxiety around vaccines. “We want to make sure that we’re not giving more fuel to people who have an excuse not to get a vaccine,” Dr. Yu said. “We certainly want to reinforce that fact that it is safe.” Dr. Belsito noted that COVID-19 vaccines do not contain aluminum.

Even on the rare chance that a patient does have a reaction to an aluminum-containing vaccine, these subcutaneous nodules resolve over time, Dr. Belsito said. In his own clinical experience, “99.99% of the time they resolve and there is no residual.” He did add that overreacting to the rash by prescribing injectable steroids can lead to steroid atrophy. In these cases, a topical steroid may be more appropriate.

All unexpected or clinically significant vaccine reactions should be reported to the Vaccine Adverse Event Reporting System, cosponsored by the Centers for Disease Control and Prevention and the Food and Drug Administration. The Clinical Immunization Project Safety Assessment Project, from the CDC, also can provide expertise and advice on aluminum-free alternatives for some vaccines.

Dr. Belsito and Dr. Yu have disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

BOSTON – The American Contact Dermatitis Society (ACDS) has selected aluminum as the Allergen of the Year for 2022. Aluminum salts, which are the major cause of allergic reactions, are “ubiquitous,” Donald Belsito, MD, professor of dermatology at Columbia University, New York, said at the annual meeting of the American Contact Dermatitis Society.

These salts can be found in sunscreen, cosmetics, dental restorations, and food, to name a few, though the most commonly identified reactions are from aluminum hydroxide, which can be found in some vaccines or preparations for allergen-specific immunotherapy. “It’s the aluminum hydroxide that seems to be more allergenic than other aluminum salts,” Dr. Belsito said in an interview.

“It’s not a dangerous allergy; It’s not a threat,” he said, “but it’s something that dermatologists need to be aware of.”

These reactions normally present as itchy nodules that can last for months and even years, like some reactions from patch testing. “We’re not talking about a vaccine allergy in such a way where people are getting anaphylaxis,” JiaDe Yu, MD, a pediatric dermatologist specializing in allergic contact dermatitis at Massachusetts General Hospital, Boston, said in an interview. “An itchy rash is what we tend to see.”

There have also been occasional reports of atopic dermatitis from aluminum in antiperspirants, astringents, as well as from the metallic aluminum.

Dr. Yu noted that aluminum allergies are not thought to be very common, but the overall prevalence is not known. Studies do suggest, however, that the allergy may be more prevalent in children. In one recent study in Sweden, 5% of children and 0.9% of adults who underwent patch testing had an aluminum contact allergy.

Recommendations for testing

Aluminum is not included in baseline patch testing in the United States, though a recent report about the allergen in the journal Dermatitis argued for its inclusion for pediatric patch testing. Both Dr. Belsito and Dr. Yu agreed that the best approach is to do targeted testing. “If there is a suspicion for it, absolutely test for it,” Dr. Yu said, but if a patient comes in with something like eyelid dermatitis or a rash after a hair care appointment, an aluminum allergy is not very likely.

Because aluminum is also present in Finn Chambers for patch testing, Dr. Belsito advised using plastic chambers in people suspected of having an aluminum allergy. He now uses only plastic chambers in children, he said, as some patients have had reactions to the Finn Chambers even if they have no history of reactions to vaccines or other aluminum-containing products.

While aluminum chloride hexahydrate (ACH) 2% in petrolatum is the commercially available preparation in patch testing, a preparation with ACH 10% is more sensitive, Dr. Belsito said. If a physician strongly suspects an aluminum allergy in a patient but the test with the ACH 2% is negative, he or she should then try a 10% solution, he noted, adding that 7-day readings are also necessary to maximize accuracy.

Vaccine safety

One of the concerns about naming aluminum as the allergen of the year is the potential to cause anxiety around vaccines. “We want to make sure that we’re not giving more fuel to people who have an excuse not to get a vaccine,” Dr. Yu said. “We certainly want to reinforce that fact that it is safe.” Dr. Belsito noted that COVID-19 vaccines do not contain aluminum.

Even on the rare chance that a patient does have a reaction to an aluminum-containing vaccine, these subcutaneous nodules resolve over time, Dr. Belsito said. In his own clinical experience, “99.99% of the time they resolve and there is no residual.” He did add that overreacting to the rash by prescribing injectable steroids can lead to steroid atrophy. In these cases, a topical steroid may be more appropriate.

All unexpected or clinically significant vaccine reactions should be reported to the Vaccine Adverse Event Reporting System, cosponsored by the Centers for Disease Control and Prevention and the Food and Drug Administration. The Clinical Immunization Project Safety Assessment Project, from the CDC, also can provide expertise and advice on aluminum-free alternatives for some vaccines.

Dr. Belsito and Dr. Yu have disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

BOSTON – The American Contact Dermatitis Society (ACDS) has selected aluminum as the Allergen of the Year for 2022. Aluminum salts, which are the major cause of allergic reactions, are “ubiquitous,” Donald Belsito, MD, professor of dermatology at Columbia University, New York, said at the annual meeting of the American Contact Dermatitis Society.

These salts can be found in sunscreen, cosmetics, dental restorations, and food, to name a few, though the most commonly identified reactions are from aluminum hydroxide, which can be found in some vaccines or preparations for allergen-specific immunotherapy. “It’s the aluminum hydroxide that seems to be more allergenic than other aluminum salts,” Dr. Belsito said in an interview.

“It’s not a dangerous allergy; It’s not a threat,” he said, “but it’s something that dermatologists need to be aware of.”

These reactions normally present as itchy nodules that can last for months and even years, like some reactions from patch testing. “We’re not talking about a vaccine allergy in such a way where people are getting anaphylaxis,” JiaDe Yu, MD, a pediatric dermatologist specializing in allergic contact dermatitis at Massachusetts General Hospital, Boston, said in an interview. “An itchy rash is what we tend to see.”

There have also been occasional reports of atopic dermatitis from aluminum in antiperspirants, astringents, as well as from the metallic aluminum.

Dr. Yu noted that aluminum allergies are not thought to be very common, but the overall prevalence is not known. Studies do suggest, however, that the allergy may be more prevalent in children. In one recent study in Sweden, 5% of children and 0.9% of adults who underwent patch testing had an aluminum contact allergy.

Recommendations for testing

Aluminum is not included in baseline patch testing in the United States, though a recent report about the allergen in the journal Dermatitis argued for its inclusion for pediatric patch testing. Both Dr. Belsito and Dr. Yu agreed that the best approach is to do targeted testing. “If there is a suspicion for it, absolutely test for it,” Dr. Yu said, but if a patient comes in with something like eyelid dermatitis or a rash after a hair care appointment, an aluminum allergy is not very likely.

Because aluminum is also present in Finn Chambers for patch testing, Dr. Belsito advised using plastic chambers in people suspected of having an aluminum allergy. He now uses only plastic chambers in children, he said, as some patients have had reactions to the Finn Chambers even if they have no history of reactions to vaccines or other aluminum-containing products.

While aluminum chloride hexahydrate (ACH) 2% in petrolatum is the commercially available preparation in patch testing, a preparation with ACH 10% is more sensitive, Dr. Belsito said. If a physician strongly suspects an aluminum allergy in a patient but the test with the ACH 2% is negative, he or she should then try a 10% solution, he noted, adding that 7-day readings are also necessary to maximize accuracy.

Vaccine safety

One of the concerns about naming aluminum as the allergen of the year is the potential to cause anxiety around vaccines. “We want to make sure that we’re not giving more fuel to people who have an excuse not to get a vaccine,” Dr. Yu said. “We certainly want to reinforce that fact that it is safe.” Dr. Belsito noted that COVID-19 vaccines do not contain aluminum.

Even on the rare chance that a patient does have a reaction to an aluminum-containing vaccine, these subcutaneous nodules resolve over time, Dr. Belsito said. In his own clinical experience, “99.99% of the time they resolve and there is no residual.” He did add that overreacting to the rash by prescribing injectable steroids can lead to steroid atrophy. In these cases, a topical steroid may be more appropriate.

All unexpected or clinically significant vaccine reactions should be reported to the Vaccine Adverse Event Reporting System, cosponsored by the Centers for Disease Control and Prevention and the Food and Drug Administration. The Clinical Immunization Project Safety Assessment Project, from the CDC, also can provide expertise and advice on aluminum-free alternatives for some vaccines.

Dr. Belsito and Dr. Yu have disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

To the Editor:

A fixed drug eruption (FDE) is a well-documented form of cutaneous hypersensitivity that typically manifests as a sharply demarcated, dusky, round to oval, edematous, red-violaceous macule or patch on the skin and mucous membranes. The lesion often resolves with residual postinflammatory hyperpigmentation, most commonly as a reaction to ingested drugs or drug components.¹ Lesions generally occur at the same anatomic site with repeated exposure to the offending drug. Typically, a single site is affected, but additional sites with more generalized involvement have been reported to occur with subsequent exposure to the offending medication. The diagnosis usually is clinical, but histopathologic findings can help confirm the diagnosis in unusual presentations. We present a novel case of a patient with an FDE from medroxyprogesterone acetate, a contraceptive injection that contains the hormone progestin.

A 35-year-old woman presented to the dermatology clinic for evaluation of a lesion on the left lower buttock of 1 year’s duration. She reported periodic swelling and associated pruritus of the lesion. She denied any growth in size, and no other similar lesions were present. The patient reported a medication history of medroxyprogesterone acetate for birth control, but she denied any other prescription or over-the-counter medication, oral supplements, or recreational drug use. Upon further inquiry, she reported that the recurrence of symptoms appeared to coincide with each administration of medroxyprogesterone acetate, which occurred approximately every 3 months. The eruption cleared between injections and recurred in the same location following subsequent injections. The lesion appeared approximately 2 weeks after the first injection (approximately 1 year prior to presentation to dermatology) and within 2 to 3 days after each subsequent injection. Physical examination revealed a 2×2-cm, circular, slightly violaceous patch on the left buttock (Figure 1). A biopsy was recommended to aid in diagnosis, and the patient was offered a topical steroid for symptomatic relief. A punch biopsy revealed subtle interface dermatitis with superficial perivascular lymphoid infiltrate and marked pigmentary incontinence consistent with an FDE (Figure 2).

An FDE was first reported in 1889 by Bourns,² and over time more implicated agents and varying clinical presentations have been linked to the disease. The FDE can be accompanied by symptoms of pruritus or paresthesia. Most cases are devoid of systemic symptoms. An FDE can be located anywhere on the body, but it most frequently manifests on the lips, face, hands, feet, and genitalia. Although the eruption often heals with residual postinflammatory hyperpigmentation, a nonpigmenting FDE due to pseudoephedrine has been reported.³

Common culprits include antibiotics (eg, sulfonamides, trimethoprim, fluoroquinolones, tetracyclines), nonsteroidal anti-inflammatory medications (eg, naproxen sodium, ibuprofen, celecoxib), barbiturates, antimalarials, and anticonvulsants. Rare cases of FDE induced by foods and food additives also have been reported.⁴ Oral fluconazole, levocetirizine dihydrochloride, loperamide, and multivitamin-mineral preparations are other rare inducers of FDE.^5-8 In 2004, Ritter and Meffert⁹ described an FDE to the green dye used in inactive oral contraceptive pills. A similar case was reported by Rea et al¹⁰ that described an FDE from the inactive sugar pills in ethinyl estradiol and levonorgestrel, which is another combined oral contraceptive.

The time between ingestion of the offending agent and the manifestation of the disease usually is 1 to 2 weeks; however, upon subsequent exposure, the disease has been reported to manifest within hours.¹ CD8⁺ memory T cells have been shown to be major players in the development of FDE and can be found along the dermoepidermal junction as part of a delayed type IV hypersensitivity reaction.¹¹ Histopathology reveals superficial and deep interstitial and perivascular infiltrates consisting of lymphocytes with admixed eosinophils and possibly neutrophils in the dermis. In the epidermis, necrotic keratinocytes can be present. In rare cases, FDE may have atypical features, such as in generalized bullous FDE and nonpigmenting FDE, the latter of which more commonly is associated with pseudoephedrine.¹

The differential diagnosis for FDE includes erythema multiforme, Stevens-Johnson syndrome/toxic epidermal necrolysis, autoimmune progesterone dermatitis, and large plaque parapsoriasis. The number and morphology of lesions in erythema multiforme help differentiate it from FDE, as erythema multiforme presents with multiple targetoid lesions. The lesions of generalized bullous FDE can be similar to those of Stevens-Johnson syndrome/toxic epidermal necrolysis, and the pigmented patches of FDE can resemble large plaque parapsoriasis.

It is important to consider any medication ingested in the 1- to 2-week period before FDE onset, including over-the-counter medications, health food supplements, and prescription medications. Discontinuation of the implicated medication or any medication potentially cross-reacting with another medication is the most important step in management. Wound care may be needed for any bullous or eroded lesions. Lesions typically resolve within a few days to weeks of stopping the offending agent. Importantly, patients should be counseled on the secondary pigment alterations that may be persistent for several months. Other treatment for FDEs is aimed at symptomatic relief and may include topical corticosteroids and oral antihistamines.¹

Medroxyprogesterone acetate is a highly effective contraceptive drug with low rates of failure.¹² It is a weak androgenic progestin that is administered as a single 150-mg intramuscular injection every 3 months and inhibits gonadotropins. Common side effects include local injection-site reactions, unscheduled bleeding, amenorrhea, weight gain, headache, and mood changes. However, FDE has not been reported as an adverse effect to medroxyprogesterone acetate, both in official US Food and Drug Administration information and in the current literature.¹²

Autoimmune progesterone dermatitis (also known as progestin hypersensitivity) is a well-characterized cyclic hypersensitivity reaction to the hormone progesterone that occurs during the luteal phase of the menstrual cycle. It is known to have a variable clinical presentation including urticaria, erythema multiforme, eczema, and angioedema.¹³ Autoimmune progesterone dermatitis also has been reported to present as an FDE.^14-16 The onset of the cutaneous manifestation often starts a few days before the onset of menses, with spontaneous resolution occurring after the onset of menstruation. The mechanism by which endogenous progesterone or other secretory products become antigenic is unknown. It has been suggested that there is an alteration in the properties of the hormone that would predispose it to be antigenic as it would not be considered self. In 2001, Warin¹⁷ proposed the following diagnostic criteria for autoimmune progesterone dermatitis: (1) skin lesions associated with menstrual cycle (premenstrual flare); (2) a positive response to the progesterone intradermal or intramuscular test; and (3) symptomatic improvement after inhibiting progesterone secretion by suppressing ovulation.¹⁷ The treatment includes antiallergy medications, progesterone desensitization, omalizumab injection, and leuprolide acetate injection.

Our case represents FDE from medroxyprogesterone acetate. Although we did not formally investigate the antigenicity of the exogenous progesterone, we postulate that the pathophysiology likely is similar to an FDE associated with endogenous progesterone. This reasoning is supported by the time course of the patient’s lesion as well as the worsening of symptoms in the days following the administration of the medication. Additionally, the patient had no history of skin lesions prior to the initiation of medroxyprogesterone acetate or similar lesions associated with her menstrual cycles.

A careful and detailed review of medication history is necessary to evaluate FDEs. Our case emphasizes that not only endogenous but also exogenous forms of progesterone may cause hypersensitivity, leading to an FDE. With more than 2 million prescriptions of medroxyprogesterone acetate written every year, dermatologists should be aware of the rare but potential risk for an FDE in patients using this medication.¹⁸

To the Editor:

A fixed drug eruption (FDE) is a well-documented form of cutaneous hypersensitivity that typically manifests as a sharply demarcated, dusky, round to oval, edematous, red-violaceous macule or patch on the skin and mucous membranes. The lesion often resolves with residual postinflammatory hyperpigmentation, most commonly as a reaction to ingested drugs or drug components.¹ Lesions generally occur at the same anatomic site with repeated exposure to the offending drug. Typically, a single site is affected, but additional sites with more generalized involvement have been reported to occur with subsequent exposure to the offending medication. The diagnosis usually is clinical, but histopathologic findings can help confirm the diagnosis in unusual presentations. We present a novel case of a patient with an FDE from medroxyprogesterone acetate, a contraceptive injection that contains the hormone progestin.

A 35-year-old woman presented to the dermatology clinic for evaluation of a lesion on the left lower buttock of 1 year’s duration. She reported periodic swelling and associated pruritus of the lesion. She denied any growth in size, and no other similar lesions were present. The patient reported a medication history of medroxyprogesterone acetate for birth control, but she denied any other prescription or over-the-counter medication, oral supplements, or recreational drug use. Upon further inquiry, she reported that the recurrence of symptoms appeared to coincide with each administration of medroxyprogesterone acetate, which occurred approximately every 3 months. The eruption cleared between injections and recurred in the same location following subsequent injections. The lesion appeared approximately 2 weeks after the first injection (approximately 1 year prior to presentation to dermatology) and within 2 to 3 days after each subsequent injection. Physical examination revealed a 2×2-cm, circular, slightly violaceous patch on the left buttock (Figure 1). A biopsy was recommended to aid in diagnosis, and the patient was offered a topical steroid for symptomatic relief. A punch biopsy revealed subtle interface dermatitis with superficial perivascular lymphoid infiltrate and marked pigmentary incontinence consistent with an FDE (Figure 2).

An FDE was first reported in 1889 by Bourns,² and over time more implicated agents and varying clinical presentations have been linked to the disease. The FDE can be accompanied by symptoms of pruritus or paresthesia. Most cases are devoid of systemic symptoms. An FDE can be located anywhere on the body, but it most frequently manifests on the lips, face, hands, feet, and genitalia. Although the eruption often heals with residual postinflammatory hyperpigmentation, a nonpigmenting FDE due to pseudoephedrine has been reported.³

Common culprits include antibiotics (eg, sulfonamides, trimethoprim, fluoroquinolones, tetracyclines), nonsteroidal anti-inflammatory medications (eg, naproxen sodium, ibuprofen, celecoxib), barbiturates, antimalarials, and anticonvulsants. Rare cases of FDE induced by foods and food additives also have been reported.⁴ Oral fluconazole, levocetirizine dihydrochloride, loperamide, and multivitamin-mineral preparations are other rare inducers of FDE.^5-8 In 2004, Ritter and Meffert⁹ described an FDE to the green dye used in inactive oral contraceptive pills. A similar case was reported by Rea et al¹⁰ that described an FDE from the inactive sugar pills in ethinyl estradiol and levonorgestrel, which is another combined oral contraceptive.

The time between ingestion of the offending agent and the manifestation of the disease usually is 1 to 2 weeks; however, upon subsequent exposure, the disease has been reported to manifest within hours.¹ CD8⁺ memory T cells have been shown to be major players in the development of FDE and can be found along the dermoepidermal junction as part of a delayed type IV hypersensitivity reaction.¹¹ Histopathology reveals superficial and deep interstitial and perivascular infiltrates consisting of lymphocytes with admixed eosinophils and possibly neutrophils in the dermis. In the epidermis, necrotic keratinocytes can be present. In rare cases, FDE may have atypical features, such as in generalized bullous FDE and nonpigmenting FDE, the latter of which more commonly is associated with pseudoephedrine.¹

The differential diagnosis for FDE includes erythema multiforme, Stevens-Johnson syndrome/toxic epidermal necrolysis, autoimmune progesterone dermatitis, and large plaque parapsoriasis. The number and morphology of lesions in erythema multiforme help differentiate it from FDE, as erythema multiforme presents with multiple targetoid lesions. The lesions of generalized bullous FDE can be similar to those of Stevens-Johnson syndrome/toxic epidermal necrolysis, and the pigmented patches of FDE can resemble large plaque parapsoriasis.

It is important to consider any medication ingested in the 1- to 2-week period before FDE onset, including over-the-counter medications, health food supplements, and prescription medications. Discontinuation of the implicated medication or any medication potentially cross-reacting with another medication is the most important step in management. Wound care may be needed for any bullous or eroded lesions. Lesions typically resolve within a few days to weeks of stopping the offending agent. Importantly, patients should be counseled on the secondary pigment alterations that may be persistent for several months. Other treatment for FDEs is aimed at symptomatic relief and may include topical corticosteroids and oral antihistamines.¹

Medroxyprogesterone acetate is a highly effective contraceptive drug with low rates of failure.¹² It is a weak androgenic progestin that is administered as a single 150-mg intramuscular injection every 3 months and inhibits gonadotropins. Common side effects include local injection-site reactions, unscheduled bleeding, amenorrhea, weight gain, headache, and mood changes. However, FDE has not been reported as an adverse effect to medroxyprogesterone acetate, both in official US Food and Drug Administration information and in the current literature.¹²

Autoimmune progesterone dermatitis (also known as progestin hypersensitivity) is a well-characterized cyclic hypersensitivity reaction to the hormone progesterone that occurs during the luteal phase of the menstrual cycle. It is known to have a variable clinical presentation including urticaria, erythema multiforme, eczema, and angioedema.¹³ Autoimmune progesterone dermatitis also has been reported to present as an FDE.^14-16 The onset of the cutaneous manifestation often starts a few days before the onset of menses, with spontaneous resolution occurring after the onset of menstruation. The mechanism by which endogenous progesterone or other secretory products become antigenic is unknown. It has been suggested that there is an alteration in the properties of the hormone that would predispose it to be antigenic as it would not be considered self. In 2001, Warin¹⁷ proposed the following diagnostic criteria for autoimmune progesterone dermatitis: (1) skin lesions associated with menstrual cycle (premenstrual flare); (2) a positive response to the progesterone intradermal or intramuscular test; and (3) symptomatic improvement after inhibiting progesterone secretion by suppressing ovulation.¹⁷ The treatment includes antiallergy medications, progesterone desensitization, omalizumab injection, and leuprolide acetate injection.

Our case represents FDE from medroxyprogesterone acetate. Although we did not formally investigate the antigenicity of the exogenous progesterone, we postulate that the pathophysiology likely is similar to an FDE associated with endogenous progesterone. This reasoning is supported by the time course of the patient’s lesion as well as the worsening of symptoms in the days following the administration of the medication. Additionally, the patient had no history of skin lesions prior to the initiation of medroxyprogesterone acetate or similar lesions associated with her menstrual cycles.

A careful and detailed review of medication history is necessary to evaluate FDEs. Our case emphasizes that not only endogenous but also exogenous forms of progesterone may cause hypersensitivity, leading to an FDE. With more than 2 million prescriptions of medroxyprogesterone acetate written every year, dermatologists should be aware of the rare but potential risk for an FDE in patients using this medication.¹⁸

To the Editor:

A fixed drug eruption (FDE) is a well-documented form of cutaneous hypersensitivity that typically manifests as a sharply demarcated, dusky, round to oval, edematous, red-violaceous macule or patch on the skin and mucous membranes. The lesion often resolves with residual postinflammatory hyperpigmentation, most commonly as a reaction to ingested drugs or drug components.¹ Lesions generally occur at the same anatomic site with repeated exposure to the offending drug. Typically, a single site is affected, but additional sites with more generalized involvement have been reported to occur with subsequent exposure to the offending medication. The diagnosis usually is clinical, but histopathologic findings can help confirm the diagnosis in unusual presentations. We present a novel case of a patient with an FDE from medroxyprogesterone acetate, a contraceptive injection that contains the hormone progestin.

A 35-year-old woman presented to the dermatology clinic for evaluation of a lesion on the left lower buttock of 1 year’s duration. She reported periodic swelling and associated pruritus of the lesion. She denied any growth in size, and no other similar lesions were present. The patient reported a medication history of medroxyprogesterone acetate for birth control, but she denied any other prescription or over-the-counter medication, oral supplements, or recreational drug use. Upon further inquiry, she reported that the recurrence of symptoms appeared to coincide with each administration of medroxyprogesterone acetate, which occurred approximately every 3 months. The eruption cleared between injections and recurred in the same location following subsequent injections. The lesion appeared approximately 2 weeks after the first injection (approximately 1 year prior to presentation to dermatology) and within 2 to 3 days after each subsequent injection. Physical examination revealed a 2×2-cm, circular, slightly violaceous patch on the left buttock (Figure 1). A biopsy was recommended to aid in diagnosis, and the patient was offered a topical steroid for symptomatic relief. A punch biopsy revealed subtle interface dermatitis with superficial perivascular lymphoid infiltrate and marked pigmentary incontinence consistent with an FDE (Figure 2).

An FDE was first reported in 1889 by Bourns,² and over time more implicated agents and varying clinical presentations have been linked to the disease. The FDE can be accompanied by symptoms of pruritus or paresthesia. Most cases are devoid of systemic symptoms. An FDE can be located anywhere on the body, but it most frequently manifests on the lips, face, hands, feet, and genitalia. Although the eruption often heals with residual postinflammatory hyperpigmentation, a nonpigmenting FDE due to pseudoephedrine has been reported.³

Common culprits include antibiotics (eg, sulfonamides, trimethoprim, fluoroquinolones, tetracyclines), nonsteroidal anti-inflammatory medications (eg, naproxen sodium, ibuprofen, celecoxib), barbiturates, antimalarials, and anticonvulsants. Rare cases of FDE induced by foods and food additives also have been reported.⁴ Oral fluconazole, levocetirizine dihydrochloride, loperamide, and multivitamin-mineral preparations are other rare inducers of FDE.^5-8 In 2004, Ritter and Meffert⁹ described an FDE to the green dye used in inactive oral contraceptive pills. A similar case was reported by Rea et al¹⁰ that described an FDE from the inactive sugar pills in ethinyl estradiol and levonorgestrel, which is another combined oral contraceptive.

The time between ingestion of the offending agent and the manifestation of the disease usually is 1 to 2 weeks; however, upon subsequent exposure, the disease has been reported to manifest within hours.¹ CD8⁺ memory T cells have been shown to be major players in the development of FDE and can be found along the dermoepidermal junction as part of a delayed type IV hypersensitivity reaction.¹¹ Histopathology reveals superficial and deep interstitial and perivascular infiltrates consisting of lymphocytes with admixed eosinophils and possibly neutrophils in the dermis. In the epidermis, necrotic keratinocytes can be present. In rare cases, FDE may have atypical features, such as in generalized bullous FDE and nonpigmenting FDE, the latter of which more commonly is associated with pseudoephedrine.¹

The differential diagnosis for FDE includes erythema multiforme, Stevens-Johnson syndrome/toxic epidermal necrolysis, autoimmune progesterone dermatitis, and large plaque parapsoriasis. The number and morphology of lesions in erythema multiforme help differentiate it from FDE, as erythema multiforme presents with multiple targetoid lesions. The lesions of generalized bullous FDE can be similar to those of Stevens-Johnson syndrome/toxic epidermal necrolysis, and the pigmented patches of FDE can resemble large plaque parapsoriasis.

It is important to consider any medication ingested in the 1- to 2-week period before FDE onset, including over-the-counter medications, health food supplements, and prescription medications. Discontinuation of the implicated medication or any medication potentially cross-reacting with another medication is the most important step in management. Wound care may be needed for any bullous or eroded lesions. Lesions typically resolve within a few days to weeks of stopping the offending agent. Importantly, patients should be counseled on the secondary pigment alterations that may be persistent for several months. Other treatment for FDEs is aimed at symptomatic relief and may include topical corticosteroids and oral antihistamines.¹

Medroxyprogesterone acetate is a highly effective contraceptive drug with low rates of failure.¹² It is a weak androgenic progestin that is administered as a single 150-mg intramuscular injection every 3 months and inhibits gonadotropins. Common side effects include local injection-site reactions, unscheduled bleeding, amenorrhea, weight gain, headache, and mood changes. However, FDE has not been reported as an adverse effect to medroxyprogesterone acetate, both in official US Food and Drug Administration information and in the current literature.¹²

Autoimmune progesterone dermatitis (also known as progestin hypersensitivity) is a well-characterized cyclic hypersensitivity reaction to the hormone progesterone that occurs during the luteal phase of the menstrual cycle. It is known to have a variable clinical presentation including urticaria, erythema multiforme, eczema, and angioedema.¹³ Autoimmune progesterone dermatitis also has been reported to present as an FDE.^14-16 The onset of the cutaneous manifestation often starts a few days before the onset of menses, with spontaneous resolution occurring after the onset of menstruation. The mechanism by which endogenous progesterone or other secretory products become antigenic is unknown. It has been suggested that there is an alteration in the properties of the hormone that would predispose it to be antigenic as it would not be considered self. In 2001, Warin¹⁷ proposed the following diagnostic criteria for autoimmune progesterone dermatitis: (1) skin lesions associated with menstrual cycle (premenstrual flare); (2) a positive response to the progesterone intradermal or intramuscular test; and (3) symptomatic improvement after inhibiting progesterone secretion by suppressing ovulation.¹⁷ The treatment includes antiallergy medications, progesterone desensitization, omalizumab injection, and leuprolide acetate injection.

Our case represents FDE from medroxyprogesterone acetate. Although we did not formally investigate the antigenicity of the exogenous progesterone, we postulate that the pathophysiology likely is similar to an FDE associated with endogenous progesterone. This reasoning is supported by the time course of the patient’s lesion as well as the worsening of symptoms in the days following the administration of the medication. Additionally, the patient had no history of skin lesions prior to the initiation of medroxyprogesterone acetate or similar lesions associated with her menstrual cycles.

A careful and detailed review of medication history is necessary to evaluate FDEs. Our case emphasizes that not only endogenous but also exogenous forms of progesterone may cause hypersensitivity, leading to an FDE. With more than 2 million prescriptions of medroxyprogesterone acetate written every year, dermatologists should be aware of the rare but potential risk for an FDE in patients using this medication.¹⁸

In patients with persistent atopic dermatitis (AD) who are taking dupilumab, is there benefit of patch testing to determine if allergic contact dermatitis (ACD) also is contributing to their disease? Results of patch testing are likely be influenced by the immunomodulatory effects of dupilumab. Similar to the recommendation for patients to refrain from using topical or systemic corticosteroids for 1 week or more prior to patch testing to eliminate false negatives, we reviewed the literature to create practice guidelines for dermatologists regarding patch testing while a patient is taking dupilumab.

Pathophysiology and Pathomechanism

Dupilumab functions through the blockade of T helper 2 (T_H2) cells; ACD is propagated through the T helper 1 (T_H1) cellular pathway. However, patients with ACD that is unresponsive to allergen avoidance and traditional therapies, such as topical and oral corticosteroids, have responded to dupilumab. The more common reports of this responsiveness are with fragrances; multiple case series described patients with ACD to fragrance mix I¹ and balsam of Peru^1,2 who improved on dupilumab when other treatments failed. There also are reports of response when ACD was secondary to nickel,^2,3p-phenylenediamine,¹ Compositae,⁴ and non–formaldehyde-releasing preservatives (non-FRPs).⁵ Therefore, not all ACD is propagated through the T_H1 cellular pathway.

As noted in these cases, ACD can be a response to an allergen whose pathogenesis involves the T_H2 pathway or when patient characteristics favor a T_H2 response. It has been suggested that AD patients are more susceptible to T_H2-mediated contact sensitization to less-potent allergens, such as fragrances.⁶

Patch Test Results

Positive patch test results for allergens have been reported while patients are on dupilumab therapy, including a few studies in which results prior to starting dupilumab were compared with those while patients were on dupilumab therapy. In a retrospective chart review of 48 patients on dupilumab for AD with persistent disease, 23 patients were patch tested before and during dupilumab therapy. In these patients, the majority of contact allergies were persistent and only 10% (13/125) of patch test–positive results resolved on dupilumab therapy.⁷ Contact allergies that resolved included those to emulsifiers (propylene glycol, Amerchol L101 [lanolin-containing products found in cosmetics and other goods], dimethylaminopropylamine), fragrances (fragrance mix I, balsam of Peru), sunscreens (sulisobenzone, phenylbenzimidazole-5-sulfonic acid), and metals (vanadium chloride, phenylmercuric acetate).⁷ The following results observed in individual cases demonstrated conflicting findings: persistence of allergy to non-FRPs (methylisothiazolinone [MI]) but resolution of allergy to formaldehyde⁸; persistence of allergy to corticosteroids (budesonide and alclometasone)⁹; persistence of allergy to an antibiotic (neomycin sulfate) but resolution of allergies to a different antibiotic (bacitracin), glues (ethyl acrylate), bleach, and glutaraldehyde⁹; persistence of nickel allergy but resolution of allergies to fragrances (cinnamic aldehyde, balsam of Peru) and non-FRPs (methylchloroisothiazolinone or MI)¹⁰; and persistence of allergies to non-FRPs (MI) and FRPs (bronopol) but resolution of allergies to nickel, fragrances (hydroperoxides of linalool), and Compositae.¹¹ Additional case reports of positive patch test results while on dupilumab but with no pretreatment results for comparison include allergies to rubber additives,^12-14 nickel,¹⁴ textile dyes,¹⁴ cosmetic and hair care additives,^12,14,15 corticosteroids,¹⁵ FRPs,¹⁵ fragrances,^15,16 emulsifiers,¹⁶ and non-FRPs.¹⁷

An evident theme in the dupilumab patch-testing literature has been that results are variable and case specific: a given patient with ACD to an allergen will respond to dupilumab treatment and have subsequent negative patch testing, while another patient will not respond to dupilumab treatment and have persistent positive patch testing. This is likely because, in certain individuals, the allergen-immune system combination shifts ACD pathogenesis from a purely T_H1 response to at least a partial T_H2 response, thus allowing for benefit from dupilumab therapy. T helper 1 cell–mediated ACD should not be affected by dupilumab; therefore, reliable results can be elucidated from patch testing despite the drug.

Final Thoughts

We propose that AD patients with residual disease after taking dupilumab undergo patch testing. Positive results indicate allergens that are not inhibited by the drug. Patients will need to follow strict allergen avoidance to resolve this component of their disease; failure to improve might suggest the result was a nonrelevant positive.

If patch testing is negative, an alternative cause for residual disease must be sought. We do not recommend stopping dupilumab prior to patch testing to avoid a disease flare from AD or possible T_H2-mediated ACD.

In patients with persistent atopic dermatitis (AD) who are taking dupilumab, is there benefit of patch testing to determine if allergic contact dermatitis (ACD) also is contributing to their disease? Results of patch testing are likely be influenced by the immunomodulatory effects of dupilumab. Similar to the recommendation for patients to refrain from using topical or systemic corticosteroids for 1 week or more prior to patch testing to eliminate false negatives, we reviewed the literature to create practice guidelines for dermatologists regarding patch testing while a patient is taking dupilumab.

Pathophysiology and Pathomechanism

Dupilumab functions through the blockade of T helper 2 (T_H2) cells; ACD is propagated through the T helper 1 (T_H1) cellular pathway. However, patients with ACD that is unresponsive to allergen avoidance and traditional therapies, such as topical and oral corticosteroids, have responded to dupilumab. The more common reports of this responsiveness are with fragrances; multiple case series described patients with ACD to fragrance mix I¹ and balsam of Peru^1,2 who improved on dupilumab when other treatments failed. There also are reports of response when ACD was secondary to nickel,^2,3p-phenylenediamine,¹ Compositae,⁴ and non–formaldehyde-releasing preservatives (non-FRPs).⁵ Therefore, not all ACD is propagated through the T_H1 cellular pathway.

As noted in these cases, ACD can be a response to an allergen whose pathogenesis involves the T_H2 pathway or when patient characteristics favor a T_H2 response. It has been suggested that AD patients are more susceptible to T_H2-mediated contact sensitization to less-potent allergens, such as fragrances.⁶

Patch Test Results

Positive patch test results for allergens have been reported while patients are on dupilumab therapy, including a few studies in which results prior to starting dupilumab were compared with those while patients were on dupilumab therapy. In a retrospective chart review of 48 patients on dupilumab for AD with persistent disease, 23 patients were patch tested before and during dupilumab therapy. In these patients, the majority of contact allergies were persistent and only 10% (13/125) of patch test–positive results resolved on dupilumab therapy.⁷ Contact allergies that resolved included those to emulsifiers (propylene glycol, Amerchol L101 [lanolin-containing products found in cosmetics and other goods], dimethylaminopropylamine), fragrances (fragrance mix I, balsam of Peru), sunscreens (sulisobenzone, phenylbenzimidazole-5-sulfonic acid), and metals (vanadium chloride, phenylmercuric acetate).⁷ The following results observed in individual cases demonstrated conflicting findings: persistence of allergy to non-FRPs (methylisothiazolinone [MI]) but resolution of allergy to formaldehyde⁸; persistence of allergy to corticosteroids (budesonide and alclometasone)⁹; persistence of allergy to an antibiotic (neomycin sulfate) but resolution of allergies to a different antibiotic (bacitracin), glues (ethyl acrylate), bleach, and glutaraldehyde⁹; persistence of nickel allergy but resolution of allergies to fragrances (cinnamic aldehyde, balsam of Peru) and non-FRPs (methylchloroisothiazolinone or MI)¹⁰; and persistence of allergies to non-FRPs (MI) and FRPs (bronopol) but resolution of allergies to nickel, fragrances (hydroperoxides of linalool), and Compositae.¹¹ Additional case reports of positive patch test results while on dupilumab but with no pretreatment results for comparison include allergies to rubber additives,^12-14 nickel,¹⁴ textile dyes,¹⁴ cosmetic and hair care additives,^12,14,15 corticosteroids,¹⁵ FRPs,¹⁵ fragrances,^15,16 emulsifiers,¹⁶ and non-FRPs.¹⁷

An evident theme in the dupilumab patch-testing literature has been that results are variable and case specific: a given patient with ACD to an allergen will respond to dupilumab treatment and have subsequent negative patch testing, while another patient will not respond to dupilumab treatment and have persistent positive patch testing. This is likely because, in certain individuals, the allergen-immune system combination shifts ACD pathogenesis from a purely T_H1 response to at least a partial T_H2 response, thus allowing for benefit from dupilumab therapy. T helper 1 cell–mediated ACD should not be affected by dupilumab; therefore, reliable results can be elucidated from patch testing despite the drug.

Final Thoughts

We propose that AD patients with residual disease after taking dupilumab undergo patch testing. Positive results indicate allergens that are not inhibited by the drug. Patients will need to follow strict allergen avoidance to resolve this component of their disease; failure to improve might suggest the result was a nonrelevant positive.

If patch testing is negative, an alternative cause for residual disease must be sought. We do not recommend stopping dupilumab prior to patch testing to avoid a disease flare from AD or possible T_H2-mediated ACD.

In patients with persistent atopic dermatitis (AD) who are taking dupilumab, is there benefit of patch testing to determine if allergic contact dermatitis (ACD) also is contributing to their disease? Results of patch testing are likely be influenced by the immunomodulatory effects of dupilumab. Similar to the recommendation for patients to refrain from using topical or systemic corticosteroids for 1 week or more prior to patch testing to eliminate false negatives, we reviewed the literature to create practice guidelines for dermatologists regarding patch testing while a patient is taking dupilumab.

Pathophysiology and Pathomechanism

Dupilumab functions through the blockade of T helper 2 (T_H2) cells; ACD is propagated through the T helper 1 (T_H1) cellular pathway. However, patients with ACD that is unresponsive to allergen avoidance and traditional therapies, such as topical and oral corticosteroids, have responded to dupilumab. The more common reports of this responsiveness are with fragrances; multiple case series described patients with ACD to fragrance mix I¹ and balsam of Peru^1,2 who improved on dupilumab when other treatments failed. There also are reports of response when ACD was secondary to nickel,^2,3p-phenylenediamine,¹ Compositae,⁴ and non–formaldehyde-releasing preservatives (non-FRPs).⁵ Therefore, not all ACD is propagated through the T_H1 cellular pathway.

As noted in these cases, ACD can be a response to an allergen whose pathogenesis involves the T_H2 pathway or when patient characteristics favor a T_H2 response. It has been suggested that AD patients are more susceptible to T_H2-mediated contact sensitization to less-potent allergens, such as fragrances.⁶

Patch Test Results

Positive patch test results for allergens have been reported while patients are on dupilumab therapy, including a few studies in which results prior to starting dupilumab were compared with those while patients were on dupilumab therapy. In a retrospective chart review of 48 patients on dupilumab for AD with persistent disease, 23 patients were patch tested before and during dupilumab therapy. In these patients, the majority of contact allergies were persistent and only 10% (13/125) of patch test–positive results resolved on dupilumab therapy.⁷ Contact allergies that resolved included those to emulsifiers (propylene glycol, Amerchol L101 [lanolin-containing products found in cosmetics and other goods], dimethylaminopropylamine), fragrances (fragrance mix I, balsam of Peru), sunscreens (sulisobenzone, phenylbenzimidazole-5-sulfonic acid), and metals (vanadium chloride, phenylmercuric acetate).⁷ The following results observed in individual cases demonstrated conflicting findings: persistence of allergy to non-FRPs (methylisothiazolinone [MI]) but resolution of allergy to formaldehyde⁸; persistence of allergy to corticosteroids (budesonide and alclometasone)⁹; persistence of allergy to an antibiotic (neomycin sulfate) but resolution of allergies to a different antibiotic (bacitracin), glues (ethyl acrylate), bleach, and glutaraldehyde⁹; persistence of nickel allergy but resolution of allergies to fragrances (cinnamic aldehyde, balsam of Peru) and non-FRPs (methylchloroisothiazolinone or MI)¹⁰; and persistence of allergies to non-FRPs (MI) and FRPs (bronopol) but resolution of allergies to nickel, fragrances (hydroperoxides of linalool), and Compositae.¹¹ Additional case reports of positive patch test results while on dupilumab but with no pretreatment results for comparison include allergies to rubber additives,^12-14 nickel,¹⁴ textile dyes,¹⁴ cosmetic and hair care additives,^12,14,15 corticosteroids,¹⁵ FRPs,¹⁵ fragrances,^15,16 emulsifiers,¹⁶ and non-FRPs.¹⁷

An evident theme in the dupilumab patch-testing literature has been that results are variable and case specific: a given patient with ACD to an allergen will respond to dupilumab treatment and have subsequent negative patch testing, while another patient will not respond to dupilumab treatment and have persistent positive patch testing. This is likely because, in certain individuals, the allergen-immune system combination shifts ACD pathogenesis from a purely T_H1 response to at least a partial T_H2 response, thus allowing for benefit from dupilumab therapy. T helper 1 cell–mediated ACD should not be affected by dupilumab; therefore, reliable results can be elucidated from patch testing despite the drug.

Final Thoughts

We propose that AD patients with residual disease after taking dupilumab undergo patch testing. Positive results indicate allergens that are not inhibited by the drug. Patients will need to follow strict allergen avoidance to resolve this component of their disease; failure to improve might suggest the result was a nonrelevant positive.

If patch testing is negative, an alternative cause for residual disease must be sought. We do not recommend stopping dupilumab prior to patch testing to avoid a disease flare from AD or possible T_H2-mediated ACD.

Practice Gap

The topical calcineurin inhibitors (TCIs) tacrolimus and pimecrolimus are US Food and Drug Administration approved for the treatment of atopic dermatitis.¹ In addition, these 2 drugs are utilized off label for many other dermatologic conditions, including vitiligo, psoriasis, and periorificial dermatitis. They can be used safely for prolonged periods and on sensitive areas, including the face.

Treatment with a TCI provides advantages over topical steroids, which can cause atrophy, telangiectasia, dyspigmentation, ocular hypertension, cataracts, and tachyphylaxis after prolonged use. Adverse events resulting from use of a TCI most commonly include transient burning, warmth, and erythema in areas of application. Patients typically acclimate to these effects after a few consecutive days of use.

Localized flushing after alcohol ingestion is a known potential side effect of TCIs¹; however, this association may be underappreciated and underreported to patients.

Counseling Patients Taking TCIs

Topical calcineurin inhibitors cause alcohol-induced flushing on areas of application (Figures 1 and 2) in approximately 3.4% to 6.9% of patients.¹ The reaction has been reported with both topical TCIs but more often is noted with tacrolimus.^2,3 Typically, flushing begins 2 to 4 weeks after treatment is initiated and within 5 to 20 minutes after alcohol intake.⁴ The phenomenon is self-limited; erythema typically resolves in 20 to 60 minutes.

Topical calcineurin inhibitors are hypothesized to cause alcohol-induced flushing by locally inhibiting acetaldehyde dehydrogenase, an enzyme necessary for alcohol metabolism. This leads to accumulation of acetaldehyde, a by-product of alcohol metabolism, which indirectly causes concentrated vasodilation by means of prostaglandins, histamines, and other vasodilatory mediators. The combination of ethanol and a TCI also might induce release of neuropeptides, which could cause vasodilation.⁴

Alcohol-related flushing commonly is seen among individuals who are aldehyde dehydrogenase 2 (ALDH2) deficient; it is sometimes accompanied by nausea, headache, and tachycardia. The same pathway is implicated in disulfiram reactions, to a more intense and systemic degree, to discourage alcohol intake.

Oral calcineurin inhibitors are not reported to cause generalized flushing, perhaps because of differences in the relative dose. For example, topical tacrolimus 0.1% is 1 mg/g that is applied to a relatively small body surface area; oral calcineurin inhibitors are dosed at a range of 1 to 15 mg for an entire person.

Techniques to Avoid Flushing

Discontinuing a TCI altogether leads to resolution of associated adverse effects, including flushing, typically within weeks to 1 month.⁵ Alternatively, oral aspirin (81 mg) might eliminate or attenuate symptoms, as documented in a double-blind, controlled trial in which relief of TCI-induced flushing after consuming wine was investigated.⁶

Another approach (albeit nontraditional) is for patients who experience this phenomenon to “wet their whistles” with an alcoholic drink before a social engagement. After flushing resolves in 20 to 60 minutes, subsequent drinks do not appear to elicit symptoms again in most patients. That said, we stop short of calling this tip “doctor’s orders.”

Practical Implication

Counseling patients who will be using a TCI—tacrolimus or pimecrolimus—about the potential for these drugs to produce localized flushing after alcohol ingestion as well as techniques for lessening or eliminating this adverse effect are important facets of their dermatologic care.

Practice Gap

The topical calcineurin inhibitors (TCIs) tacrolimus and pimecrolimus are US Food and Drug Administration approved for the treatment of atopic dermatitis.¹ In addition, these 2 drugs are utilized off label for many other dermatologic conditions, including vitiligo, psoriasis, and periorificial dermatitis. They can be used safely for prolonged periods and on sensitive areas, including the face.

Treatment with a TCI provides advantages over topical steroids, which can cause atrophy, telangiectasia, dyspigmentation, ocular hypertension, cataracts, and tachyphylaxis after prolonged use. Adverse events resulting from use of a TCI most commonly include transient burning, warmth, and erythema in areas of application. Patients typically acclimate to these effects after a few consecutive days of use.

Localized flushing after alcohol ingestion is a known potential side effect of TCIs¹; however, this association may be underappreciated and underreported to patients.

Counseling Patients Taking TCIs

Topical calcineurin inhibitors cause alcohol-induced flushing on areas of application (Figures 1 and 2) in approximately 3.4% to 6.9% of patients.¹ The reaction has been reported with both topical TCIs but more often is noted with tacrolimus.^2,3 Typically, flushing begins 2 to 4 weeks after treatment is initiated and within 5 to 20 minutes after alcohol intake.⁴ The phenomenon is self-limited; erythema typically resolves in 20 to 60 minutes.

Topical calcineurin inhibitors are hypothesized to cause alcohol-induced flushing by locally inhibiting acetaldehyde dehydrogenase, an enzyme necessary for alcohol metabolism. This leads to accumulation of acetaldehyde, a by-product of alcohol metabolism, which indirectly causes concentrated vasodilation by means of prostaglandins, histamines, and other vasodilatory mediators. The combination of ethanol and a TCI also might induce release of neuropeptides, which could cause vasodilation.⁴

Alcohol-related flushing commonly is seen among individuals who are aldehyde dehydrogenase 2 (ALDH2) deficient; it is sometimes accompanied by nausea, headache, and tachycardia. The same pathway is implicated in disulfiram reactions, to a more intense and systemic degree, to discourage alcohol intake.

Oral calcineurin inhibitors are not reported to cause generalized flushing, perhaps because of differences in the relative dose. For example, topical tacrolimus 0.1% is 1 mg/g that is applied to a relatively small body surface area; oral calcineurin inhibitors are dosed at a range of 1 to 15 mg for an entire person.

Techniques to Avoid Flushing

Discontinuing a TCI altogether leads to resolution of associated adverse effects, including flushing, typically within weeks to 1 month.⁵ Alternatively, oral aspirin (81 mg) might eliminate or attenuate symptoms, as documented in a double-blind, controlled trial in which relief of TCI-induced flushing after consuming wine was investigated.⁶

Another approach (albeit nontraditional) is for patients who experience this phenomenon to “wet their whistles” with an alcoholic drink before a social engagement. After flushing resolves in 20 to 60 minutes, subsequent drinks do not appear to elicit symptoms again in most patients. That said, we stop short of calling this tip “doctor’s orders.”

Practical Implication

Counseling patients who will be using a TCI—tacrolimus or pimecrolimus—about the potential for these drugs to produce localized flushing after alcohol ingestion as well as techniques for lessening or eliminating this adverse effect are important facets of their dermatologic care.

Practice Gap

The topical calcineurin inhibitors (TCIs) tacrolimus and pimecrolimus are US Food and Drug Administration approved for the treatment of atopic dermatitis.¹ In addition, these 2 drugs are utilized off label for many other dermatologic conditions, including vitiligo, psoriasis, and periorificial dermatitis. They can be used safely for prolonged periods and on sensitive areas, including the face.

Treatment with a TCI provides advantages over topical steroids, which can cause atrophy, telangiectasia, dyspigmentation, ocular hypertension, cataracts, and tachyphylaxis after prolonged use. Adverse events resulting from use of a TCI most commonly include transient burning, warmth, and erythema in areas of application. Patients typically acclimate to these effects after a few consecutive days of use.

Localized flushing after alcohol ingestion is a known potential side effect of TCIs¹; however, this association may be underappreciated and underreported to patients.

Counseling Patients Taking TCIs

Topical calcineurin inhibitors cause alcohol-induced flushing on areas of application (Figures 1 and 2) in approximately 3.4% to 6.9% of patients.¹ The reaction has been reported with both topical TCIs but more often is noted with tacrolimus.^2,3 Typically, flushing begins 2 to 4 weeks after treatment is initiated and within 5 to 20 minutes after alcohol intake.⁴ The phenomenon is self-limited; erythema typically resolves in 20 to 60 minutes.

Topical calcineurin inhibitors are hypothesized to cause alcohol-induced flushing by locally inhibiting acetaldehyde dehydrogenase, an enzyme necessary for alcohol metabolism. This leads to accumulation of acetaldehyde, a by-product of alcohol metabolism, which indirectly causes concentrated vasodilation by means of prostaglandins, histamines, and other vasodilatory mediators. The combination of ethanol and a TCI also might induce release of neuropeptides, which could cause vasodilation.⁴

Alcohol-related flushing commonly is seen among individuals who are aldehyde dehydrogenase 2 (ALDH2) deficient; it is sometimes accompanied by nausea, headache, and tachycardia. The same pathway is implicated in disulfiram reactions, to a more intense and systemic degree, to discourage alcohol intake.

Oral calcineurin inhibitors are not reported to cause generalized flushing, perhaps because of differences in the relative dose. For example, topical tacrolimus 0.1% is 1 mg/g that is applied to a relatively small body surface area; oral calcineurin inhibitors are dosed at a range of 1 to 15 mg for an entire person.

Techniques to Avoid Flushing

Discontinuing a TCI altogether leads to resolution of associated adverse effects, including flushing, typically within weeks to 1 month.⁵ Alternatively, oral aspirin (81 mg) might eliminate or attenuate symptoms, as documented in a double-blind, controlled trial in which relief of TCI-induced flushing after consuming wine was investigated.⁶

Another approach (albeit nontraditional) is for patients who experience this phenomenon to “wet their whistles” with an alcoholic drink before a social engagement. After flushing resolves in 20 to 60 minutes, subsequent drinks do not appear to elicit symptoms again in most patients. That said, we stop short of calling this tip “doctor’s orders.”

Practical Implication

Counseling patients who will be using a TCI—tacrolimus or pimecrolimus—about the potential for these drugs to produce localized flushing after alcohol ingestion as well as techniques for lessening or eliminating this adverse effect are important facets of their dermatologic care.

Global climate change is hitting home for dermatologists, according to a recent survey in which the majority of participants said their patients are already being impacted.

Almost 80% of the 148 participants who responded to an electronic survey reported this belief.

The survey was designed and distributed to the membership of various dermatological organizations by Misha Rosenbach, MD, and coauthors. The results were published in the British Journal of Dermatology.

Asked also about specific types of climate-driven phenomena with a current – or future – impact on their patients, 80.1% reported that they believed that increased exposure to ultraviolet radiation (UVR) is impactful, or will be. Changes in temporal or geographic patterns of vector-borne illnesses were affirmed by 78.7%, and an increase in social displacement caused by extreme weather or other events was affirmed by 67.1% as having an impact on their patients currently or in the future.

Other phenomena affirmed by respondents as already having an impact or impacting patients in the future were an increased incidence of heat exposure or heat-related illness (58.2%); an increase in rates of inflammatory skin disease flares (43.2%); increased incidence of waterborne infections (42.5%); and increased rates of allergic contact dermatitis (29.5%).

The survey was sent to the membership of the American Society of Dermatologic Surgery, the Society for Pediatric Dermatology, the Society for Investigative Dermatology, and the American Academy of Dermatology’s Climate Change Expert Resource Group (ERG), among other organizations.

The study design and membership overlap made it impossible to calculate a response rate, the authors said, but they estimated it to be about 10%.

Almost all respondents were from the United States, and most (86.3%) practiced in an academic setting. The findings are similar to those of an online survey of members of the International Society of Dermatology (ISD), published in 2020, which found that 89% of 158 respondents believed climate change will impact the incidence of skin diseases in their area.

“Physicians, including dermatologists, are starting to understand the impact of the climate crisis on both their patients and themselves ... both through lived experiences and [issues raised] more in the scientific literature and in meetings,” Dr. Rosenbach, associate professor of dermatology at the University of Pennsylvania, Philadelphia, said in an interview.

A majority of participants in the U.S. survey agreed they have a responsibility to bring awareness of the health effects of climate change to patients (77.2%) and to policymakers (88.6%). (In the ISD survey, 88% said they believed that dermatologists should play an advocacy role in climate change-related issues).

Only a minority of respondents in the U.S. survey said that they would feel comfortable discussing climate change with their patients (37.2%). Almost one-third of the respondents said they would like to be better informed about climate change before doing so. And 81.8% said they would like to read more about the dermatological effects of climate change in scientific journals.

“There continues to be unfilled interest in education and advocacy regarding climate change, suggesting a ‘practice gap’ even among dermatologists,” Dr. Rosenbach and his colleagues wrote, noting opportunities for professional organizations and journals to provide more resources and “actionable items” regarding climate change.

Some dermatologists have been taking action, in the meantime, to reduce the carbon footprint of their practices and institutions. Reductions in facility energy consumption, and reductions in medical waste/optimization of recycling, were each reported by more than one-third of survey respondents.

And almost half indicated that their practice or institution had increased capacity for telemedicine or telecommuting in response to climate change. Only 8% said their practice or institution had divested from fossil fuel stocks and/or bonds.

“There are a lot of sustainability-in-medicine solutions that are actually cost-neutral or cost-saving for practices,” said Dr. Rosenbach, who is a founder and co-chair of the AAD’s ERG on Climate Change and Environmental Issues.

Research in dermatology is starting to quantify the environmental impact of some of these changes. In a research letter also published in the British Journal of Dermatology, researchers from Cardiff University and the department of dermatology at University Hospital of Wales, described how they determined that reusable surgical packs used for skin surgery are more sustainable than single-use packs because of their reduced cost and reduced greenhouse gas emissions.

Such single-site reports are “early feeders” into what will become a stream of larger studies quantifying the impact of measures taken in dermatology, Dr. Rosenbach said.

Across medicine, there is evidence that health care professionals are now seeing climate change as a threat to their patients. In a multinational survey published last year in The Lancet Planetary Health, 77% of 3,977 participants said that climate change will cause a moderate or great deal of harm for their patients.

Climate change will be discussed at the AAD’s annual meeting in late March in a session devoted to the topic, and as part of a broader session on controversies in dermatology.

Dr. Rosenbach and two of the five authors of the dermatology research letter are members of the AAD’s ERG on climate change, but in the publication they noted that they were not writing on behalf of the AAD. None of the authors reported any disclosures, and there was no funding source for the survey.

Global climate change is hitting home for dermatologists, according to a recent survey in which the majority of participants said their patients are already being impacted.

Almost 80% of the 148 participants who responded to an electronic survey reported this belief.

The survey was designed and distributed to the membership of various dermatological organizations by Misha Rosenbach, MD, and coauthors. The results were published in the British Journal of Dermatology.

Asked also about specific types of climate-driven phenomena with a current – or future – impact on their patients, 80.1% reported that they believed that increased exposure to ultraviolet radiation (UVR) is impactful, or will be. Changes in temporal or geographic patterns of vector-borne illnesses were affirmed by 78.7%, and an increase in social displacement caused by extreme weather or other events was affirmed by 67.1% as having an impact on their patients currently or in the future.

Other phenomena affirmed by respondents as already having an impact or impacting patients in the future were an increased incidence of heat exposure or heat-related illness (58.2%); an increase in rates of inflammatory skin disease flares (43.2%); increased incidence of waterborne infections (42.5%); and increased rates of allergic contact dermatitis (29.5%).

The survey was sent to the membership of the American Society of Dermatologic Surgery, the Society for Pediatric Dermatology, the Society for Investigative Dermatology, and the American Academy of Dermatology’s Climate Change Expert Resource Group (ERG), among other organizations.

The study design and membership overlap made it impossible to calculate a response rate, the authors said, but they estimated it to be about 10%.

Almost all respondents were from the United States, and most (86.3%) practiced in an academic setting. The findings are similar to those of an online survey of members of the International Society of Dermatology (ISD), published in 2020, which found that 89% of 158 respondents believed climate change will impact the incidence of skin diseases in their area.

“Physicians, including dermatologists, are starting to understand the impact of the climate crisis on both their patients and themselves ... both through lived experiences and [issues raised] more in the scientific literature and in meetings,” Dr. Rosenbach, associate professor of dermatology at the University of Pennsylvania, Philadelphia, said in an interview.

A majority of participants in the U.S. survey agreed they have a responsibility to bring awareness of the health effects of climate change to patients (77.2%) and to policymakers (88.6%). (In the ISD survey, 88% said they believed that dermatologists should play an advocacy role in climate change-related issues).

Only a minority of respondents in the U.S. survey said that they would feel comfortable discussing climate change with their patients (37.2%). Almost one-third of the respondents said they would like to be better informed about climate change before doing so. And 81.8% said they would like to read more about the dermatological effects of climate change in scientific journals.

“There continues to be unfilled interest in education and advocacy regarding climate change, suggesting a ‘practice gap’ even among dermatologists,” Dr. Rosenbach and his colleagues wrote, noting opportunities for professional organizations and journals to provide more resources and “actionable items” regarding climate change.

Some dermatologists have been taking action, in the meantime, to reduce the carbon footprint of their practices and institutions. Reductions in facility energy consumption, and reductions in medical waste/optimization of recycling, were each reported by more than one-third of survey respondents.

And almost half indicated that their practice or institution had increased capacity for telemedicine or telecommuting in response to climate change. Only 8% said their practice or institution had divested from fossil fuel stocks and/or bonds.

“There are a lot of sustainability-in-medicine solutions that are actually cost-neutral or cost-saving for practices,” said Dr. Rosenbach, who is a founder and co-chair of the AAD’s ERG on Climate Change and Environmental Issues.

Research in dermatology is starting to quantify the environmental impact of some of these changes. In a research letter also published in the British Journal of Dermatology, researchers from Cardiff University and the department of dermatology at University Hospital of Wales, described how they determined that reusable surgical packs used for skin surgery are more sustainable than single-use packs because of their reduced cost and reduced greenhouse gas emissions.

Such single-site reports are “early feeders” into what will become a stream of larger studies quantifying the impact of measures taken in dermatology, Dr. Rosenbach said.

Across medicine, there is evidence that health care professionals are now seeing climate change as a threat to their patients. In a multinational survey published last year in The Lancet Planetary Health, 77% of 3,977 participants said that climate change will cause a moderate or great deal of harm for their patients.

Climate change will be discussed at the AAD’s annual meeting in late March in a session devoted to the topic, and as part of a broader session on controversies in dermatology.

Dr. Rosenbach and two of the five authors of the dermatology research letter are members of the AAD’s ERG on climate change, but in the publication they noted that they were not writing on behalf of the AAD. None of the authors reported any disclosures, and there was no funding source for the survey.

Global climate change is hitting home for dermatologists, according to a recent survey in which the majority of participants said their patients are already being impacted.

Almost 80% of the 148 participants who responded to an electronic survey reported this belief.

The survey was designed and distributed to the membership of various dermatological organizations by Misha Rosenbach, MD, and coauthors. The results were published in the British Journal of Dermatology.

Asked also about specific types of climate-driven phenomena with a current – or future – impact on their patients, 80.1% reported that they believed that increased exposure to ultraviolet radiation (UVR) is impactful, or will be. Changes in temporal or geographic patterns of vector-borne illnesses were affirmed by 78.7%, and an increase in social displacement caused by extreme weather or other events was affirmed by 67.1% as having an impact on their patients currently or in the future.

Other phenomena affirmed by respondents as already having an impact or impacting patients in the future were an increased incidence of heat exposure or heat-related illness (58.2%); an increase in rates of inflammatory skin disease flares (43.2%); increased incidence of waterborne infections (42.5%); and increased rates of allergic contact dermatitis (29.5%).

The survey was sent to the membership of the American Society of Dermatologic Surgery, the Society for Pediatric Dermatology, the Society for Investigative Dermatology, and the American Academy of Dermatology’s Climate Change Expert Resource Group (ERG), among other organizations.

The study design and membership overlap made it impossible to calculate a response rate, the authors said, but they estimated it to be about 10%.

Almost all respondents were from the United States, and most (86.3%) practiced in an academic setting. The findings are similar to those of an online survey of members of the International Society of Dermatology (ISD), published in 2020, which found that 89% of 158 respondents believed climate change will impact the incidence of skin diseases in their area.

“Physicians, including dermatologists, are starting to understand the impact of the climate crisis on both their patients and themselves ... both through lived experiences and [issues raised] more in the scientific literature and in meetings,” Dr. Rosenbach, associate professor of dermatology at the University of Pennsylvania, Philadelphia, said in an interview.

A majority of participants in the U.S. survey agreed they have a responsibility to bring awareness of the health effects of climate change to patients (77.2%) and to policymakers (88.6%). (In the ISD survey, 88% said they believed that dermatologists should play an advocacy role in climate change-related issues).

Only a minority of respondents in the U.S. survey said that they would feel comfortable discussing climate change with their patients (37.2%). Almost one-third of the respondents said they would like to be better informed about climate change before doing so. And 81.8% said they would like to read more about the dermatological effects of climate change in scientific journals.

“There continues to be unfilled interest in education and advocacy regarding climate change, suggesting a ‘practice gap’ even among dermatologists,” Dr. Rosenbach and his colleagues wrote, noting opportunities for professional organizations and journals to provide more resources and “actionable items” regarding climate change.

Some dermatologists have been taking action, in the meantime, to reduce the carbon footprint of their practices and institutions. Reductions in facility energy consumption, and reductions in medical waste/optimization of recycling, were each reported by more than one-third of survey respondents.

And almost half indicated that their practice or institution had increased capacity for telemedicine or telecommuting in response to climate change. Only 8% said their practice or institution had divested from fossil fuel stocks and/or bonds.

“There are a lot of sustainability-in-medicine solutions that are actually cost-neutral or cost-saving for practices,” said Dr. Rosenbach, who is a founder and co-chair of the AAD’s ERG on Climate Change and Environmental Issues.

Research in dermatology is starting to quantify the environmental impact of some of these changes. In a research letter also published in the British Journal of Dermatology, researchers from Cardiff University and the department of dermatology at University Hospital of Wales, described how they determined that reusable surgical packs used for skin surgery are more sustainable than single-use packs because of their reduced cost and reduced greenhouse gas emissions.

Such single-site reports are “early feeders” into what will become a stream of larger studies quantifying the impact of measures taken in dermatology, Dr. Rosenbach said.

Across medicine, there is evidence that health care professionals are now seeing climate change as a threat to their patients. In a multinational survey published last year in The Lancet Planetary Health, 77% of 3,977 participants said that climate change will cause a moderate or great deal of harm for their patients.

Climate change will be discussed at the AAD’s annual meeting in late March in a session devoted to the topic, and as part of a broader session on controversies in dermatology.

Dr. Rosenbach and two of the five authors of the dermatology research letter are members of the AAD’s ERG on climate change, but in the publication they noted that they were not writing on behalf of the AAD. None of the authors reported any disclosures, and there was no funding source for the survey.

To the Editor:

A 71-year-old Hispanic man with a history of vitiligo presented with an acute-onset blistering rash on the face, arms, and hands. Physical examination demonstrated photodistributed erythematous plaques with overlying vesicles and erosions with hemorrhagic crust on the face, neck, dorsal aspects of the hands, and wrists (Figure). Further history revealed that the patient applied a new cream that was recommended to treat vitiligo the night before the rash onset; he obtained the cream from a Central American market without a prescription. He had gone running in the park without any form of sun protection and then developed the rash within several hours. He denied taking any other medications or supplements. The involvement of sun-protected areas (ie, upper eyelids, nasolabial folds, submental area) was explained when the patient further elaborated that he had performed supine exercises during his outdoor recreation. He brought his new cream into the clinic, which was found to contain prescription-strength methoxsalen (8-methoxypsoralen), confirming the diagnosis of acute phototoxic contact dermatitis. The acute reaction had subsided, and the patient already had discontinued the causative agent. He was counseled on further avoidance of the cream and sun-protective measures.

The photosensitizing properties of certain compounds have been harnessed for therapeutic purposes. For example, psoralen plus UVA therapy has been used for psoriasis and vitiligo and photodynamic therapy for actinic keratoses and superficial nonmelanoma skin cancers.¹ However, these agents can induce severe phototoxicity if UV light exposure is not carefully monitored, as seen in our patient. This case is a classic example of phototoxic contact dermatitis and highlights the importance of obtaining a detailed patient history to allow for proper diagnosis and identification of the causative agent. Importantly, because prescription-strength topical medications are readily available over-the-counter, particularly in stores specializing in international goods, patients should be questioned about the use of all topical and systemic medications, both prescription and nonprescription.²

To the Editor:

A 71-year-old Hispanic man with a history of vitiligo presented with an acute-onset blistering rash on the face, arms, and hands. Physical examination demonstrated photodistributed erythematous plaques with overlying vesicles and erosions with hemorrhagic crust on the face, neck, dorsal aspects of the hands, and wrists (Figure). Further history revealed that the patient applied a new cream that was recommended to treat vitiligo the night before the rash onset; he obtained the cream from a Central American market without a prescription. He had gone running in the park without any form of sun protection and then developed the rash within several hours. He denied taking any other medications or supplements. The involvement of sun-protected areas (ie, upper eyelids, nasolabial folds, submental area) was explained when the patient further elaborated that he had performed supine exercises during his outdoor recreation. He brought his new cream into the clinic, which was found to contain prescription-strength methoxsalen (8-methoxypsoralen), confirming the diagnosis of acute phototoxic contact dermatitis. The acute reaction had subsided, and the patient already had discontinued the causative agent. He was counseled on further avoidance of the cream and sun-protective measures.

The photosensitizing properties of certain compounds have been harnessed for therapeutic purposes. For example, psoralen plus UVA therapy has been used for psoriasis and vitiligo and photodynamic therapy for actinic keratoses and superficial nonmelanoma skin cancers.¹ However, these agents can induce severe phototoxicity if UV light exposure is not carefully monitored, as seen in our patient. This case is a classic example of phototoxic contact dermatitis and highlights the importance of obtaining a detailed patient history to allow for proper diagnosis and identification of the causative agent. Importantly, because prescription-strength topical medications are readily available over-the-counter, particularly in stores specializing in international goods, patients should be questioned about the use of all topical and systemic medications, both prescription and nonprescription.²

To the Editor:

A 71-year-old Hispanic man with a history of vitiligo presented with an acute-onset blistering rash on the face, arms, and hands. Physical examination demonstrated photodistributed erythematous plaques with overlying vesicles and erosions with hemorrhagic crust on the face, neck, dorsal aspects of the hands, and wrists (Figure). Further history revealed that the patient applied a new cream that was recommended to treat vitiligo the night before the rash onset; he obtained the cream from a Central American market without a prescription. He had gone running in the park without any form of sun protection and then developed the rash within several hours. He denied taking any other medications or supplements. The involvement of sun-protected areas (ie, upper eyelids, nasolabial folds, submental area) was explained when the patient further elaborated that he had performed supine exercises during his outdoor recreation. He brought his new cream into the clinic, which was found to contain prescription-strength methoxsalen (8-methoxypsoralen), confirming the diagnosis of acute phototoxic contact dermatitis. The acute reaction had subsided, and the patient already had discontinued the causative agent. He was counseled on further avoidance of the cream and sun-protective measures.

The photosensitizing properties of certain compounds have been harnessed for therapeutic purposes. For example, psoralen plus UVA therapy has been used for psoriasis and vitiligo and photodynamic therapy for actinic keratoses and superficial nonmelanoma skin cancers.¹ However, these agents can induce severe phototoxicity if UV light exposure is not carefully monitored, as seen in our patient. This case is a classic example of phototoxic contact dermatitis and highlights the importance of obtaining a detailed patient history to allow for proper diagnosis and identification of the causative agent. Importantly, because prescription-strength topical medications are readily available over-the-counter, particularly in stores specializing in international goods, patients should be questioned about the use of all topical and systemic medications, both prescription and nonprescription.²

In the first part of this 2-part series (Cutis. 2021;108:271-275), we discussed topical medicament allergic contact dermatitis (ACD) from acne and rosacea medications, antimicrobials, antihistamines, and topical pain preparations. In part 2 of this series, we focus on topical corticosteroids, immunomodulators, and anesthetics.

Corticosteroids

Given their anti-inflammatory and immune-modulating effects, topical corticosteroids are utilized for the treatment of contact dermatitis and yet also are frequent culprits of ACD. The North American Contact Dermatitis Group (NACDG) demonstrated a 4% frequency of positive patch tests to at least one corticosteroid from 2007 to 2014; the relevant allergens were tixocortol pivalate (TP)(2.3%), budesonide (0.9%), hydrocortisone-17-butyrate (0.4%), clobetasol-17-propionate (0.3%), and desoximetasone (0.2%).¹ Corticosteroid contact allergy can be difficult to recognize and may present as a flare of the underlying condition being treated. Clinically, these rashes may demonstrate an edge effect, characterized by pronounced dermatitis adjacent to and surrounding the treatment area due to concentrated anti-inflammatory effects in the center.

Traditionally, corticosteroids are divided into 4 basic structural groups—classes A, B, C, and D—based on the Coopman et al² classification (Table). The class D corticosteroids were further subdivided into classes D1, defined by C16-methyl substitution and halogenation of the B ring, and D2, which lacks the aforementioned substitutions.⁴ However, more recently Baeck et al⁵ simplified this classification into 3 main groups of steroids based on molecular modeling in combination with patch test results. Group 1 combines the nonmethylated and (mostly) nonhalogenated class A and D2 molecules plus budesonide; group 2 accounts for some halogenated class B molecules with the C16, C17 cis ketal or diol structure; and group 3 includes halogenated and C16-methylated molecules from classes C and D1.⁴ For the purposes of this review, discussion of classes A through D refers to the Coopman et al² classification, and groups 1 through 3 refers to Baeck et al.⁵

Tixocortol pivalate is used as a surrogate marker for hydrocortisone allergy and other class A corticosteroids and is part of the group 1 steroid classification. Interestingly, patients with TP-positive patch tests may not exhibit signs or symptoms of ACD from the use of hydrocortisone products. Repeat open application testing (ROAT) or provocative use testing may elicit a positive response in these patients, especially with the use of hydrocortisone cream (vs ointment), likely due to greater transepidermal penetration.⁶ There is little consensus on the optimal concentration of TP for patch testing. Although TP 1% often is recommended, studies have shown mixed findings of notable differences between high (1% petrolatum) and low (0.1% petrolatum) concentrations of TP.^7,8

Budesonide also is part of group 1 and is a marker for contact allergy to class B corticosteroids, such as triamcinolone and fluocinonide. Cross-reactions between budesonide and other corticosteroids traditionally classified as group B may be explained by structural similarities, whereas cross-reactions with certain class D corticosteroids, such as hydrocortisone-17-butyrate, may be better explained by the diastereomer composition of budesonide.^9,10 In a European study, budesonide 0.01% and TP 0.1% included in the European Baseline Series detected 85% (23/27) of cases of corticosteroid allergies.¹¹ Use of inhaled budesonide can provoke recall dermatitis and therefore should be avoided in allergic patients.¹²

Testing for ACD to topical steroids is complex, as the potent anti-inflammatory properties of these medications can complicate results. Selecting the appropriate test, vehicle, and concentration can help avoid false negatives. Although intradermal testing previously was thought to be superior to patch testing in detecting topical corticosteroid contact allergy, newer data have demonstrated strong concordance between the two methods.^13,14 The risk for skin atrophy, particularly with the use of suspensions, limits the use of intradermal testing.¹⁴ An ethanol vehicle is recommended for patch testing, except when testing with TP or budesonide when petrolatum provides greater corticosteroid stability.^14-16 An irritant pattern or a rim effect on patch testing often is considered positive when testing corticosteroids, as the effect of the steroid itself can diminish a positive reaction. As a result, 0.1% dilutions sometimes are favored over 1% test concentrations.^14,15,17 Late readings (>7 days) may be necessary to detect positive reactions in both adults and children.^18,19

The authors (M.R., A.R.A.) find these varied classifications of steroids daunting (and somewhat confusing!). In general, when ACD to topical steroids is suspected, in addition to standard patch testing with a corticosteroid series, ROAT of the suspected steroid may be necessary, as the rules of steroid classification may not be reproducible in the real world. For patients with only corticosteroid allergy, calcineurin inhibitors are a safe alternative.

Immunomodulators

Calcipotriol is a vitamin D analogue commonly used to treat psoriasis. Although it is a well-known irritant, ACD to topical calcipotriol rarely has been reported.^20-23 Topical calcipotriol does not seem to cross-react with other vitamin D analogues, including tacalcitol and calcitriol.^21,24 Based on the literature and the nonirritant reactive thresholds described by Fullerton et al,²⁵ recommended patch test concentrations of calcipotriol in isopropanol are 2 to 10 µg/mL. Given its immunomodulating effects, calcipotriol may suppress contact hypersensitization from other allergens, similar to the effects seen with UV radiation.²⁶

Calcineurin inhibitors act on the nuclear factor of activated T cells signaling pathway, resulting in downstream suppression of proinflammatory cytokines. Contact allergy to these topical medications is rare and mainly has involved pimecrolimus.^27-30 In one case, a patient with a previously documented topical tacrolimus contact allergy demonstrated cross-reactivity with pimecrolimus on a double-blinded, right-vs-left ROAT, as well as by patch testing with pimecrolimus cream 1%, which was only weakly positive (+).²⁷ Patch test concentrations of 2.5% or higher may be required to elicit positive reactions to tacrolimus, as shown in one case where this was attributed to high molecular weight and poor extrafacial skin absorption of tacrolimus.³⁰ In an unusual case, a patient reacted positively to patch testing and ROAT using pimecrolimus cream 1% but not pimecrolimus 1% to 5% in petrolatum or alcohol nor the individual excipients, illustrating the importance of testing with both active and inactive ingredients.²⁹

Anesthetics

Local anesthetics can be separated into 2 main groups—amides and esters—based on their chemical structures. From 2001 to 2004, the NACDG patch tested 10,061 patients and found 344 (3.4%) with a positive reaction to at least one topical anesthetic.³¹ We will discuss some of the allergic cutaneous reactions associated with topical benzocaine (an ester) and lidocaine and prilocaine (amides).

According to the NACDG, the estimated prevalence of topical benzocaine allergy from 2001 to 2018 was roughly 3%.³² Allergic contact dermatitis has been reported in patients who used topical benzocaine to treat localized pain disorders, including herpes zoster and dental pain.^33,34 Benzocaine may be used in the anogenital region in the form of antihemorrhoidal creams and in condoms and is a considerably more common allergen in those with anogenital dermatitis compared to those without.^35-38 Although cross-reactions within the same anesthetic group are common, clinicians also should be aware of the potential for concomitant sensitivity between unrelated local anesthetics.^39-41

From 2001 to 2018, the prevalence of ACD to topical lidocaine was estimated to be 7.9%, according to the NACDG.³² A topical anesthetic containing both lidocaine and prilocaine often is used preprocedurally and can be a source of ACD. Interestingly, several cases of ACD to combination lidocaine/prilocaine cream demonstrated positive patch tests to prilocaine but not lidocaine, despite their structural similarities.^42-44 One case report described simultaneous positive reactions to both prilocaine 5% and lidocaine 1%.⁴⁵

There are a few key points to consider when working up contact allergy to local anesthetics. Patients who develop positive patch test reactions to a local anesthetic should undergo further testing to better understand alternatives and future use. As previously mentioned, ACD to one anesthetic does not necessarily preclude the use of other related anesthetics. Intradermal testing may help differentiate immediate and delayed-type allergic reactions to local anesthetics and should therefore follow positive patch tests.⁴⁶ Importantly, a delayed reading (ie, after day 6 or 7) also should be performed as part of intradermal testing. Patients with positive patch tests but negative intradermal test results may be able to tolerate systemic anesthetic use.⁴⁷

Patch Testing for Potential Medicament ACD

In this article, we touched on several topical medications that have nuanced patch testing specifications given their immunomodulating effects. A simplified outline of recommended patch test concentrations is provided in the eTable, and we encourage you to revisit these useful resources as needed. In many cases, referral to a specialized patch test clinic may be necessary. Although they are not reviewed in this article, always consider inactive ingredients such as preservatives, softening agents, and emulsifiers in the setting of medicament dermatitis, as they also may be culprits of ACD.

Final Interpretation

In this 2-part series, we covered ACD to several common topical drugs with a focus on active ingredients as the source of allergy, and yet this is just the tip of the iceberg. Topical medicaments are prevalent in the field of dermatology, and associated cases of ACD have been reported proportionately. Consider ACD when topical medication efficacy plateaus, triggers new-onset dermatitis, or seems to exacerbate an underlying dermatitis.

In the first part of this 2-part series (Cutis. 2021;108:271-275), we discussed topical medicament allergic contact dermatitis (ACD) from acne and rosacea medications, antimicrobials, antihistamines, and topical pain preparations. In part 2 of this series, we focus on topical corticosteroids, immunomodulators, and anesthetics.

Corticosteroids

Given their anti-inflammatory and immune-modulating effects, topical corticosteroids are utilized for the treatment of contact dermatitis and yet also are frequent culprits of ACD. The North American Contact Dermatitis Group (NACDG) demonstrated a 4% frequency of positive patch tests to at least one corticosteroid from 2007 to 2014; the relevant allergens were tixocortol pivalate (TP)(2.3%), budesonide (0.9%), hydrocortisone-17-butyrate (0.4%), clobetasol-17-propionate (0.3%), and desoximetasone (0.2%).¹ Corticosteroid contact allergy can be difficult to recognize and may present as a flare of the underlying condition being treated. Clinically, these rashes may demonstrate an edge effect, characterized by pronounced dermatitis adjacent to and surrounding the treatment area due to concentrated anti-inflammatory effects in the center.

Traditionally, corticosteroids are divided into 4 basic structural groups—classes A, B, C, and D—based on the Coopman et al² classification (Table). The class D corticosteroids were further subdivided into classes D1, defined by C16-methyl substitution and halogenation of the B ring, and D2, which lacks the aforementioned substitutions.⁴ However, more recently Baeck et al⁵ simplified this classification into 3 main groups of steroids based on molecular modeling in combination with patch test results. Group 1 combines the nonmethylated and (mostly) nonhalogenated class A and D2 molecules plus budesonide; group 2 accounts for some halogenated class B molecules with the C16, C17 cis ketal or diol structure; and group 3 includes halogenated and C16-methylated molecules from classes C and D1.⁴ For the purposes of this review, discussion of classes A through D refers to the Coopman et al² classification, and groups 1 through 3 refers to Baeck et al.⁵

Tixocortol pivalate is used as a surrogate marker for hydrocortisone allergy and other class A corticosteroids and is part of the group 1 steroid classification. Interestingly, patients with TP-positive patch tests may not exhibit signs or symptoms of ACD from the use of hydrocortisone products. Repeat open application testing (ROAT) or provocative use testing may elicit a positive response in these patients, especially with the use of hydrocortisone cream (vs ointment), likely due to greater transepidermal penetration.⁶ There is little consensus on the optimal concentration of TP for patch testing. Although TP 1% often is recommended, studies have shown mixed findings of notable differences between high (1% petrolatum) and low (0.1% petrolatum) concentrations of TP.^7,8

Budesonide also is part of group 1 and is a marker for contact allergy to class B corticosteroids, such as triamcinolone and fluocinonide. Cross-reactions between budesonide and other corticosteroids traditionally classified as group B may be explained by structural similarities, whereas cross-reactions with certain class D corticosteroids, such as hydrocortisone-17-butyrate, may be better explained by the diastereomer composition of budesonide.^9,10 In a European study, budesonide 0.01% and TP 0.1% included in the European Baseline Series detected 85% (23/27) of cases of corticosteroid allergies.¹¹ Use of inhaled budesonide can provoke recall dermatitis and therefore should be avoided in allergic patients.¹²

Testing for ACD to topical steroids is complex, as the potent anti-inflammatory properties of these medications can complicate results. Selecting the appropriate test, vehicle, and concentration can help avoid false negatives. Although intradermal testing previously was thought to be superior to patch testing in detecting topical corticosteroid contact allergy, newer data have demonstrated strong concordance between the two methods.^13,14 The risk for skin atrophy, particularly with the use of suspensions, limits the use of intradermal testing.¹⁴ An ethanol vehicle is recommended for patch testing, except when testing with TP or budesonide when petrolatum provides greater corticosteroid stability.^14-16 An irritant pattern or a rim effect on patch testing often is considered positive when testing corticosteroids, as the effect of the steroid itself can diminish a positive reaction. As a result, 0.1% dilutions sometimes are favored over 1% test concentrations.^14,15,17 Late readings (>7 days) may be necessary to detect positive reactions in both adults and children.^18,19

The authors (M.R., A.R.A.) find these varied classifications of steroids daunting (and somewhat confusing!). In general, when ACD to topical steroids is suspected, in addition to standard patch testing with a corticosteroid series, ROAT of the suspected steroid may be necessary, as the rules of steroid classification may not be reproducible in the real world. For patients with only corticosteroid allergy, calcineurin inhibitors are a safe alternative.

Immunomodulators

Calcipotriol is a vitamin D analogue commonly used to treat psoriasis. Although it is a well-known irritant, ACD to topical calcipotriol rarely has been reported.^20-23 Topical calcipotriol does not seem to cross-react with other vitamin D analogues, including tacalcitol and calcitriol.^21,24 Based on the literature and the nonirritant reactive thresholds described by Fullerton et al,²⁵ recommended patch test concentrations of calcipotriol in isopropanol are 2 to 10 µg/mL. Given its immunomodulating effects, calcipotriol may suppress contact hypersensitization from other allergens, similar to the effects seen with UV radiation.²⁶

Calcineurin inhibitors act on the nuclear factor of activated T cells signaling pathway, resulting in downstream suppression of proinflammatory cytokines. Contact allergy to these topical medications is rare and mainly has involved pimecrolimus.^27-30 In one case, a patient with a previously documented topical tacrolimus contact allergy demonstrated cross-reactivity with pimecrolimus on a double-blinded, right-vs-left ROAT, as well as by patch testing with pimecrolimus cream 1%, which was only weakly positive (+).²⁷ Patch test concentrations of 2.5% or higher may be required to elicit positive reactions to tacrolimus, as shown in one case where this was attributed to high molecular weight and poor extrafacial skin absorption of tacrolimus.³⁰ In an unusual case, a patient reacted positively to patch testing and ROAT using pimecrolimus cream 1% but not pimecrolimus 1% to 5% in petrolatum or alcohol nor the individual excipients, illustrating the importance of testing with both active and inactive ingredients.²⁹

Anesthetics

Local anesthetics can be separated into 2 main groups—amides and esters—based on their chemical structures. From 2001 to 2004, the NACDG patch tested 10,061 patients and found 344 (3.4%) with a positive reaction to at least one topical anesthetic.³¹ We will discuss some of the allergic cutaneous reactions associated with topical benzocaine (an ester) and lidocaine and prilocaine (amides).

According to the NACDG, the estimated prevalence of topical benzocaine allergy from 2001 to 2018 was roughly 3%.³² Allergic contact dermatitis has been reported in patients who used topical benzocaine to treat localized pain disorders, including herpes zoster and dental pain.^33,34 Benzocaine may be used in the anogenital region in the form of antihemorrhoidal creams and in condoms and is a considerably more common allergen in those with anogenital dermatitis compared to those without.^35-38 Although cross-reactions within the same anesthetic group are common, clinicians also should be aware of the potential for concomitant sensitivity between unrelated local anesthetics.^39-41

From 2001 to 2018, the prevalence of ACD to topical lidocaine was estimated to be 7.9%, according to the NACDG.³² A topical anesthetic containing both lidocaine and prilocaine often is used preprocedurally and can be a source of ACD. Interestingly, several cases of ACD to combination lidocaine/prilocaine cream demonstrated positive patch tests to prilocaine but not lidocaine, despite their structural similarities.^42-44 One case report described simultaneous positive reactions to both prilocaine 5% and lidocaine 1%.⁴⁵

There are a few key points to consider when working up contact allergy to local anesthetics. Patients who develop positive patch test reactions to a local anesthetic should undergo further testing to better understand alternatives and future use. As previously mentioned, ACD to one anesthetic does not necessarily preclude the use of other related anesthetics. Intradermal testing may help differentiate immediate and delayed-type allergic reactions to local anesthetics and should therefore follow positive patch tests.⁴⁶ Importantly, a delayed reading (ie, after day 6 or 7) also should be performed as part of intradermal testing. Patients with positive patch tests but negative intradermal test results may be able to tolerate systemic anesthetic use.⁴⁷

Patch Testing for Potential Medicament ACD

In this article, we touched on several topical medications that have nuanced patch testing specifications given their immunomodulating effects. A simplified outline of recommended patch test concentrations is provided in the eTable, and we encourage you to revisit these useful resources as needed. In many cases, referral to a specialized patch test clinic may be necessary. Although they are not reviewed in this article, always consider inactive ingredients such as preservatives, softening agents, and emulsifiers in the setting of medicament dermatitis, as they also may be culprits of ACD.

Final Interpretation

In this 2-part series, we covered ACD to several common topical drugs with a focus on active ingredients as the source of allergy, and yet this is just the tip of the iceberg. Topical medicaments are prevalent in the field of dermatology, and associated cases of ACD have been reported proportionately. Consider ACD when topical medication efficacy plateaus, triggers new-onset dermatitis, or seems to exacerbate an underlying dermatitis.

In the first part of this 2-part series (Cutis. 2021;108:271-275), we discussed topical medicament allergic contact dermatitis (ACD) from acne and rosacea medications, antimicrobials, antihistamines, and topical pain preparations. In part 2 of this series, we focus on topical corticosteroids, immunomodulators, and anesthetics.

Corticosteroids

Given their anti-inflammatory and immune-modulating effects, topical corticosteroids are utilized for the treatment of contact dermatitis and yet also are frequent culprits of ACD. The North American Contact Dermatitis Group (NACDG) demonstrated a 4% frequency of positive patch tests to at least one corticosteroid from 2007 to 2014; the relevant allergens were tixocortol pivalate (TP)(2.3%), budesonide (0.9%), hydrocortisone-17-butyrate (0.4%), clobetasol-17-propionate (0.3%), and desoximetasone (0.2%).¹ Corticosteroid contact allergy can be difficult to recognize and may present as a flare of the underlying condition being treated. Clinically, these rashes may demonstrate an edge effect, characterized by pronounced dermatitis adjacent to and surrounding the treatment area due to concentrated anti-inflammatory effects in the center.

Traditionally, corticosteroids are divided into 4 basic structural groups—classes A, B, C, and D—based on the Coopman et al² classification (Table). The class D corticosteroids were further subdivided into classes D1, defined by C16-methyl substitution and halogenation of the B ring, and D2, which lacks the aforementioned substitutions.⁴ However, more recently Baeck et al⁵ simplified this classification into 3 main groups of steroids based on molecular modeling in combination with patch test results. Group 1 combines the nonmethylated and (mostly) nonhalogenated class A and D2 molecules plus budesonide; group 2 accounts for some halogenated class B molecules with the C16, C17 cis ketal or diol structure; and group 3 includes halogenated and C16-methylated molecules from classes C and D1.⁴ For the purposes of this review, discussion of classes A through D refers to the Coopman et al² classification, and groups 1 through 3 refers to Baeck et al.⁵

Tixocortol pivalate is used as a surrogate marker for hydrocortisone allergy and other class A corticosteroids and is part of the group 1 steroid classification. Interestingly, patients with TP-positive patch tests may not exhibit signs or symptoms of ACD from the use of hydrocortisone products. Repeat open application testing (ROAT) or provocative use testing may elicit a positive response in these patients, especially with the use of hydrocortisone cream (vs ointment), likely due to greater transepidermal penetration.⁶ There is little consensus on the optimal concentration of TP for patch testing. Although TP 1% often is recommended, studies have shown mixed findings of notable differences between high (1% petrolatum) and low (0.1% petrolatum) concentrations of TP.^7,8

Budesonide also is part of group 1 and is a marker for contact allergy to class B corticosteroids, such as triamcinolone and fluocinonide. Cross-reactions between budesonide and other corticosteroids traditionally classified as group B may be explained by structural similarities, whereas cross-reactions with certain class D corticosteroids, such as hydrocortisone-17-butyrate, may be better explained by the diastereomer composition of budesonide.^9,10 In a European study, budesonide 0.01% and TP 0.1% included in the European Baseline Series detected 85% (23/27) of cases of corticosteroid allergies.¹¹ Use of inhaled budesonide can provoke recall dermatitis and therefore should be avoided in allergic patients.¹²

Testing for ACD to topical steroids is complex, as the potent anti-inflammatory properties of these medications can complicate results. Selecting the appropriate test, vehicle, and concentration can help avoid false negatives. Although intradermal testing previously was thought to be superior to patch testing in detecting topical corticosteroid contact allergy, newer data have demonstrated strong concordance between the two methods.^13,14 The risk for skin atrophy, particularly with the use of suspensions, limits the use of intradermal testing.¹⁴ An ethanol vehicle is recommended for patch testing, except when testing with TP or budesonide when petrolatum provides greater corticosteroid stability.^14-16 An irritant pattern or a rim effect on patch testing often is considered positive when testing corticosteroids, as the effect of the steroid itself can diminish a positive reaction. As a result, 0.1% dilutions sometimes are favored over 1% test concentrations.^14,15,17 Late readings (>7 days) may be necessary to detect positive reactions in both adults and children.^18,19

The authors (M.R., A.R.A.) find these varied classifications of steroids daunting (and somewhat confusing!). In general, when ACD to topical steroids is suspected, in addition to standard patch testing with a corticosteroid series, ROAT of the suspected steroid may be necessary, as the rules of steroid classification may not be reproducible in the real world. For patients with only corticosteroid allergy, calcineurin inhibitors are a safe alternative.

Immunomodulators

Calcipotriol is a vitamin D analogue commonly used to treat psoriasis. Although it is a well-known irritant, ACD to topical calcipotriol rarely has been reported.^20-23 Topical calcipotriol does not seem to cross-react with other vitamin D analogues, including tacalcitol and calcitriol.^21,24 Based on the literature and the nonirritant reactive thresholds described by Fullerton et al,²⁵ recommended patch test concentrations of calcipotriol in isopropanol are 2 to 10 µg/mL. Given its immunomodulating effects, calcipotriol may suppress contact hypersensitization from other allergens, similar to the effects seen with UV radiation.²⁶

Calcineurin inhibitors act on the nuclear factor of activated T cells signaling pathway, resulting in downstream suppression of proinflammatory cytokines. Contact allergy to these topical medications is rare and mainly has involved pimecrolimus.^27-30 In one case, a patient with a previously documented topical tacrolimus contact allergy demonstrated cross-reactivity with pimecrolimus on a double-blinded, right-vs-left ROAT, as well as by patch testing with pimecrolimus cream 1%, which was only weakly positive (+).²⁷ Patch test concentrations of 2.5% or higher may be required to elicit positive reactions to tacrolimus, as shown in one case where this was attributed to high molecular weight and poor extrafacial skin absorption of tacrolimus.³⁰ In an unusual case, a patient reacted positively to patch testing and ROAT using pimecrolimus cream 1% but not pimecrolimus 1% to 5% in petrolatum or alcohol nor the individual excipients, illustrating the importance of testing with both active and inactive ingredients.²⁹

Anesthetics

Local anesthetics can be separated into 2 main groups—amides and esters—based on their chemical structures. From 2001 to 2004, the NACDG patch tested 10,061 patients and found 344 (3.4%) with a positive reaction to at least one topical anesthetic.³¹ We will discuss some of the allergic cutaneous reactions associated with topical benzocaine (an ester) and lidocaine and prilocaine (amides).

According to the NACDG, the estimated prevalence of topical benzocaine allergy from 2001 to 2018 was roughly 3%.³² Allergic contact dermatitis has been reported in patients who used topical benzocaine to treat localized pain disorders, including herpes zoster and dental pain.^33,34 Benzocaine may be used in the anogenital region in the form of antihemorrhoidal creams and in condoms and is a considerably more common allergen in those with anogenital dermatitis compared to those without.^35-38 Although cross-reactions within the same anesthetic group are common, clinicians also should be aware of the potential for concomitant sensitivity between unrelated local anesthetics.^39-41

From 2001 to 2018, the prevalence of ACD to topical lidocaine was estimated to be 7.9%, according to the NACDG.³² A topical anesthetic containing both lidocaine and prilocaine often is used preprocedurally and can be a source of ACD. Interestingly, several cases of ACD to combination lidocaine/prilocaine cream demonstrated positive patch tests to prilocaine but not lidocaine, despite their structural similarities.^42-44 One case report described simultaneous positive reactions to both prilocaine 5% and lidocaine 1%.⁴⁵

There are a few key points to consider when working up contact allergy to local anesthetics. Patients who develop positive patch test reactions to a local anesthetic should undergo further testing to better understand alternatives and future use. As previously mentioned, ACD to one anesthetic does not necessarily preclude the use of other related anesthetics. Intradermal testing may help differentiate immediate and delayed-type allergic reactions to local anesthetics and should therefore follow positive patch tests.⁴⁶ Importantly, a delayed reading (ie, after day 6 or 7) also should be performed as part of intradermal testing. Patients with positive patch tests but negative intradermal test results may be able to tolerate systemic anesthetic use.⁴⁷

Patch Testing for Potential Medicament ACD

In this article, we touched on several topical medications that have nuanced patch testing specifications given their immunomodulating effects. A simplified outline of recommended patch test concentrations is provided in the eTable, and we encourage you to revisit these useful resources as needed. In many cases, referral to a specialized patch test clinic may be necessary. Although they are not reviewed in this article, always consider inactive ingredients such as preservatives, softening agents, and emulsifiers in the setting of medicament dermatitis, as they also may be culprits of ACD.

Final Interpretation

In this 2-part series, we covered ACD to several common topical drugs with a focus on active ingredients as the source of allergy, and yet this is just the tip of the iceberg. Topical medicaments are prevalent in the field of dermatology, and associated cases of ACD have been reported proportionately. Consider ACD when topical medication efficacy plateaus, triggers new-onset dermatitis, or seems to exacerbate an underlying dermatitis.