Alexis Tracy, MD

Practice Gap

Frictional, symmetric, asymptomatic, erythematous macules of the hands and feet can be mistaken for perniolike lesions associated with COVID-19, commonly known as COVID toes. However, in a low-risk setting without other associated symptoms or concerning findings on examination, consider and inquire about frequent use of a swimming pool. This activity can lead to localized pressure- and friction-induced erythema on palmar and plantar surfaces, called “pool palms and feet,” expanding on the already-named lesion “pool palms”—an entity that is distinct from COVID toes.

Technique for Diagnosis

We evaluated 4 patients in the outpatient setting who presented with localized, patterned, erythematous lesions of the hands or feet, or both, during the COVID-19 pandemic. The parents of our patients were concerned that the rash represented “COVID fingers and toes,” which are perniolike lesions seen in patients with suspected or confirmed current or prior COVID-19.¹

Pernio, also known as chilblains, is a superficial inflammatory vascular response, usually in the setting of exposure to cold.² This phenomenon usually appears as erythematous or violaceous macules and papules on acral skin, particularly on the dorsum and sides of the fingers and toes, with edema, vesiculation, and ulceration in more severe cases. Initially, it is pruritic and painful at times.

With COVID toes, there often is a delayed presentation of perniolike lesions after the onset of other COVID-19 symptoms, such as fever, cough, headache, and sore throat.^2,3 It has been described more often in younger patients and those with milder disease. However, because our patients had no known exposure to SARS-CoV-2 or other associated symptoms, our suspicion was low.

The 4 patients we evaluated—aged 4 to 12 years and in their usual good health—had blanchable erythema of the palmar fingers, palmar eminences of both hands, and plantar surfaces of both feet (Figure). There was no swelling or tenderness, and the lesions had no violaceous coloration, vesiculation, or ulceration. There was no associated pruritus or pain. One patient reported rough texture and mild peeling of the hands.

Upon further inquiry, the patients reported a history of extended time spent in home swimming pools, including holding on to the edge of the pool, due to limitation of activities because of COVID restrictions. One parent noted that the pool that caused the rash had a rough nonslip surface, whereas other pools that the children used, which had a smoother surface, caused no problems.

The morphology of symmetric blanching erythema in areas of pressure and friction, in the absence of a notable medical history, signs, or symptoms, was consistent with a diagnosis of pool palms, which has been described in the medical literature.^4-9 Pool palms can affect the palms and soles, which are subject to substantial friction, especially when a person is getting in and out of the pool. There is a general consensus that pool palms is a frictional dermatitis affecting children because the greater fragility of their skin is exacerbated by immersion in water.^4-9

Pool palms and feet is benign. Only supportive care, with cessation of swimming and application of emollients, is necessary.

Apart from COVID-19, other conditions to consider in a patient with erythematous lesions of the palms and soles include eczematous dermatitis; neutrophilic eccrine hidradenitis; and, if lesions are vesicular, hand-foot-and-mouth disease. Juvenile plantar dermatosis, which is thought to be due to moisture with occlusion in shoes, also might be considered but is distinguished by more scales and fissures that can be painful.

Location of the lesions is a critical variable. The patients we evaluated had lesions primarily on palmar and plantar surfaces where contact with pool surfaces was greatest, such as at bony prominences, which supported a diagnosis of frictional dermatitis, such as pool palms and feet. A thorough history and physical examination are helpful in determining the diagnosis.

Practical Implications

It is important to consider and recognize this localized pressure phenomenon of pool palms and feet, thus obviating an unnecessary workup or therapeutic interventions. Specifically, a finding of erythematous asymptomatic macules, with or without scaling, on bony prominences of the palms and soles is more consistent with pool palms and feet.

Pernio and COVID toes both present as erythematous to violaceous papules and macules, with edema, vesiculation, and ulceration in severe cases, often on the dorsum and sides of fingers and toes; typically the conditions are pruritic and painful at times.

Explaining the diagnosis of pool palms and feet and sharing one’s experience with similar cases might help alleviate parental fear and anxiety during the COVID-19 pandemic.

Practice Gap

Frictional, symmetric, asymptomatic, erythematous macules of the hands and feet can be mistaken for perniolike lesions associated with COVID-19, commonly known as COVID toes. However, in a low-risk setting without other associated symptoms or concerning findings on examination, consider and inquire about frequent use of a swimming pool. This activity can lead to localized pressure- and friction-induced erythema on palmar and plantar surfaces, called “pool palms and feet,” expanding on the already-named lesion “pool palms”—an entity that is distinct from COVID toes.

Technique for Diagnosis

We evaluated 4 patients in the outpatient setting who presented with localized, patterned, erythematous lesions of the hands or feet, or both, during the COVID-19 pandemic. The parents of our patients were concerned that the rash represented “COVID fingers and toes,” which are perniolike lesions seen in patients with suspected or confirmed current or prior COVID-19.¹

Pernio, also known as chilblains, is a superficial inflammatory vascular response, usually in the setting of exposure to cold.² This phenomenon usually appears as erythematous or violaceous macules and papules on acral skin, particularly on the dorsum and sides of the fingers and toes, with edema, vesiculation, and ulceration in more severe cases. Initially, it is pruritic and painful at times.

With COVID toes, there often is a delayed presentation of perniolike lesions after the onset of other COVID-19 symptoms, such as fever, cough, headache, and sore throat.^2,3 It has been described more often in younger patients and those with milder disease. However, because our patients had no known exposure to SARS-CoV-2 or other associated symptoms, our suspicion was low.

The 4 patients we evaluated—aged 4 to 12 years and in their usual good health—had blanchable erythema of the palmar fingers, palmar eminences of both hands, and plantar surfaces of both feet (Figure). There was no swelling or tenderness, and the lesions had no violaceous coloration, vesiculation, or ulceration. There was no associated pruritus or pain. One patient reported rough texture and mild peeling of the hands.

Upon further inquiry, the patients reported a history of extended time spent in home swimming pools, including holding on to the edge of the pool, due to limitation of activities because of COVID restrictions. One parent noted that the pool that caused the rash had a rough nonslip surface, whereas other pools that the children used, which had a smoother surface, caused no problems.

The morphology of symmetric blanching erythema in areas of pressure and friction, in the absence of a notable medical history, signs, or symptoms, was consistent with a diagnosis of pool palms, which has been described in the medical literature.^4-9 Pool palms can affect the palms and soles, which are subject to substantial friction, especially when a person is getting in and out of the pool. There is a general consensus that pool palms is a frictional dermatitis affecting children because the greater fragility of their skin is exacerbated by immersion in water.^4-9

Pool palms and feet is benign. Only supportive care, with cessation of swimming and application of emollients, is necessary.

Apart from COVID-19, other conditions to consider in a patient with erythematous lesions of the palms and soles include eczematous dermatitis; neutrophilic eccrine hidradenitis; and, if lesions are vesicular, hand-foot-and-mouth disease. Juvenile plantar dermatosis, which is thought to be due to moisture with occlusion in shoes, also might be considered but is distinguished by more scales and fissures that can be painful.

Location of the lesions is a critical variable. The patients we evaluated had lesions primarily on palmar and plantar surfaces where contact with pool surfaces was greatest, such as at bony prominences, which supported a diagnosis of frictional dermatitis, such as pool palms and feet. A thorough history and physical examination are helpful in determining the diagnosis.

Practical Implications

It is important to consider and recognize this localized pressure phenomenon of pool palms and feet, thus obviating an unnecessary workup or therapeutic interventions. Specifically, a finding of erythematous asymptomatic macules, with or without scaling, on bony prominences of the palms and soles is more consistent with pool palms and feet.

Pernio and COVID toes both present as erythematous to violaceous papules and macules, with edema, vesiculation, and ulceration in severe cases, often on the dorsum and sides of fingers and toes; typically the conditions are pruritic and painful at times.

Explaining the diagnosis of pool palms and feet and sharing one’s experience with similar cases might help alleviate parental fear and anxiety during the COVID-19 pandemic.

Practice Gap

Frictional, symmetric, asymptomatic, erythematous macules of the hands and feet can be mistaken for perniolike lesions associated with COVID-19, commonly known as COVID toes. However, in a low-risk setting without other associated symptoms or concerning findings on examination, consider and inquire about frequent use of a swimming pool. This activity can lead to localized pressure- and friction-induced erythema on palmar and plantar surfaces, called “pool palms and feet,” expanding on the already-named lesion “pool palms”—an entity that is distinct from COVID toes.

Technique for Diagnosis

We evaluated 4 patients in the outpatient setting who presented with localized, patterned, erythematous lesions of the hands or feet, or both, during the COVID-19 pandemic. The parents of our patients were concerned that the rash represented “COVID fingers and toes,” which are perniolike lesions seen in patients with suspected or confirmed current or prior COVID-19.¹

Pernio, also known as chilblains, is a superficial inflammatory vascular response, usually in the setting of exposure to cold.² This phenomenon usually appears as erythematous or violaceous macules and papules on acral skin, particularly on the dorsum and sides of the fingers and toes, with edema, vesiculation, and ulceration in more severe cases. Initially, it is pruritic and painful at times.

With COVID toes, there often is a delayed presentation of perniolike lesions after the onset of other COVID-19 symptoms, such as fever, cough, headache, and sore throat.^2,3 It has been described more often in younger patients and those with milder disease. However, because our patients had no known exposure to SARS-CoV-2 or other associated symptoms, our suspicion was low.

The 4 patients we evaluated—aged 4 to 12 years and in their usual good health—had blanchable erythema of the palmar fingers, palmar eminences of both hands, and plantar surfaces of both feet (Figure). There was no swelling or tenderness, and the lesions had no violaceous coloration, vesiculation, or ulceration. There was no associated pruritus or pain. One patient reported rough texture and mild peeling of the hands.

Upon further inquiry, the patients reported a history of extended time spent in home swimming pools, including holding on to the edge of the pool, due to limitation of activities because of COVID restrictions. One parent noted that the pool that caused the rash had a rough nonslip surface, whereas other pools that the children used, which had a smoother surface, caused no problems.

The morphology of symmetric blanching erythema in areas of pressure and friction, in the absence of a notable medical history, signs, or symptoms, was consistent with a diagnosis of pool palms, which has been described in the medical literature.^4-9 Pool palms can affect the palms and soles, which are subject to substantial friction, especially when a person is getting in and out of the pool. There is a general consensus that pool palms is a frictional dermatitis affecting children because the greater fragility of their skin is exacerbated by immersion in water.^4-9

Pool palms and feet is benign. Only supportive care, with cessation of swimming and application of emollients, is necessary.

Apart from COVID-19, other conditions to consider in a patient with erythematous lesions of the palms and soles include eczematous dermatitis; neutrophilic eccrine hidradenitis; and, if lesions are vesicular, hand-foot-and-mouth disease. Juvenile plantar dermatosis, which is thought to be due to moisture with occlusion in shoes, also might be considered but is distinguished by more scales and fissures that can be painful.

Location of the lesions is a critical variable. The patients we evaluated had lesions primarily on palmar and plantar surfaces where contact with pool surfaces was greatest, such as at bony prominences, which supported a diagnosis of frictional dermatitis, such as pool palms and feet. A thorough history and physical examination are helpful in determining the diagnosis.

Practical Implications

It is important to consider and recognize this localized pressure phenomenon of pool palms and feet, thus obviating an unnecessary workup or therapeutic interventions. Specifically, a finding of erythematous asymptomatic macules, with or without scaling, on bony prominences of the palms and soles is more consistent with pool palms and feet.

Pernio and COVID toes both present as erythematous to violaceous papules and macules, with edema, vesiculation, and ulceration in severe cases, often on the dorsum and sides of fingers and toes; typically the conditions are pruritic and painful at times.

Explaining the diagnosis of pool palms and feet and sharing one’s experience with similar cases might help alleviate parental fear and anxiety during the COVID-19 pandemic.

Atopic dermatitis (AD) is a chronic, pruritic, inflammatory skin disease that occurs most frequently in children but also affects many adolescents and adults. There has been a tremendous evolution of knowledge in AD, with insights into pathogenesis, epidemiology, impact of disease, and new therapies. A variety of studies examine the epidemiology of AD and associated comorbidities. The broad developments in disease state research are reflected in new publication numbers of AD citations on PubMed. A PubMed search of articles indexed for MEDLINE at the end of 2010 using the term atopic dermatitis would have shown 965 citations during the preceding 1-year period. In the 1-year period of June 2019 to June 2020, there were more than 2000 articles. The large body of research includes work of great significance in pediatric AD, and in this article we review recent findings that are important in understanding the progress being made in the field.

Epidemiology and Comorbidities

The epidemiology of AD has evolved over the last few decades, with emerging trends and novel insights into the burden of disease.¹ In a recent cross-sectional study on the epidemiology of AD in children aged 6 to 11 years, the 1-year diagnosed AD prevalence estimates worldwide included the following: United States, 10.0%; Canada, 13.3%; the EU5 Countries, 15.5%; Japan, 10.3%; and all countries studied, 12.2%.² Another recent paper that analyzed data from the Fragile Families and Child Wellbeing Study showed that the prevalence and persistence of AD in urban US children was 15.0%.³Although pediatric AD may spontaneously remit over time, disease continuing into adolescence and adulthood is common. Paternoster et al⁴ studied the longitudinal course of AD in children from 2 birth cohort prospective studies, showing distinct AD phenotypes having differing course trajectories over time. Disease subsets included patients with early-onset-persistent and early-onset-late-resolving disease.⁴ Whether phenotyping or subgroup analysis can be used to predict disease course or risk for development of comorbidities is unknown, but it is interesting to consider how such work could influence tailoring of specific therapies to early disease presentation.

Atopic dermatitis poses a serious public health burden owing to its high prevalence, considerable morbidity and disability, increased health care utilization, and cost of care.¹ Recent studies have found notably higher rates of multiple medical and mental health comorbidities in both children and adults with AD, including infections, atopic comorbidities (eg, allergic rhinitis, asthma, food allergies), eye diseases (eg, keratitis, conjunctivitis, keratoconus), and possible cardiovascular diseases and autoimmune disorders.^1,5-9 Allergic comorbidities are quite common in pediatric AD patients.¹⁰ In a recent study examining the efficacy and safety of dupilumab monotherapy in 251 adolescents with moderate to severe inadequately controlled AD, most had comorbid type 2 diseases including asthma (53.6%), food allergies (60.8%), and allergic rhinitis (65.6%).¹¹

Quality of Life/Life Impact of AD

Pediatric AD has a major impact on the quality of life of patients and their families.¹² The well-being and development of children are strongly influenced by the physical and psychosocial health of parents/guardians. Two studies by Ramirez and colleagues^13,14 published in 2019 examined sleep disturbances and exhaustion in mothers of children with AD. Data for the studies came from the Avon Longitudinal Study of Parents and Children. Children with active AD reported worse sleep quality than those without AD, with nearly 50% higher odds of sleep-quality disturbances. Analysis of the cohort data from 11,649 mother-child pairs who were followed up with a time-varying measure of child AD activity and severity as well as self-reported maternal sleep measures repeated at multiple time points for children aged 6 months to 11 years showed that mothers of children with AD reported difficulty falling asleep, subjectively insufficient sleep, and daytime exhaustion throughout the first 11 years of childhood.^13,14 These data suggest that sleep disturbance may be a family affair.

A cross-sectional, real-world study on the burden of AD in children aged 6 to 11 years assessed by self-report demonstrated a substantial and multidimensional impact of AD, including itch, sleep disturbance, skin pain, and health-related quality-of-life impact, as well as comorbidities and school productivity losses. The burden associated with AD was remarkable and increased with disease severity.¹⁵

Drucker et al¹⁶ completed a comprehensive literature review on the burden of AD, summarized as a report for the National Eczema Association. Quality-of-life impact on pediatric patients included high rates of emotional distress; social isolation; depression; limitations in activities due to lesions with fear of triggers; and behavioral problems such as irritability, crying, and sleep disturbance resulting in difficulty performing at school.¹⁶ The psychological impact on children as well as emotional and behavioral difficulties may impact the ability for parents/guardians to implement treatment plans.¹⁷

There is a striking association between mental health disorders and AD in the US pediatric population, with a clear dose-dependent relationship that has been observed between the prevalence of a mental health disorder and the reported severity of the skin disease. Data suggest children with AD may be at increased risk for developing mental health disorders. The National Survey of Children’s Health found statistically significant increases in the likelihood of attention deficit hyperactivity disorder (odds ratio [OR], 1.87), depression (OR, 1.81), anxiety (OR, 1.77), conduct disorder (OR, 1.87), and autism (OR, 3.04).⁶

Evolving Practices and Therapies

Bathing Practices
There has long been much controversy regarding best bathing habits for patients with AD. In a 2009 study, cutaneous hydration was quantified after various bathing and moisturizing regimens.¹⁸ The study showed clear benefits of emollient application on skin hydration, either after bathing or without bathing. Bathing followed by emollient applications did not decrease skin hydration in contrast to bathing without emollient application.¹⁸

There are limited studies evaluating bathing frequency in pediatric patients, and many families receive conflicting information regarding best practice. In one study that surveyed 354 parents, more than 75% of parents/guardians who had seen multiple providers for their child’s AD reported a substantial amount of confusion and frustration from conflicting advice on bathing frequency.¹⁹ Cardona et al²⁰ undertook a randomized clinical trial of frequent bathing and moisturizing vs less-frequent bathing and moisturizing in pediatric patients with AD aged 6 months to 11 years. Patients were divided into 2 groups: 1 being bathed twice daily with immediate moisturizer application and the other being bathed twice weekly followed by moisturization, then a switch to the other method. Patients used standardized topical corticosteroids (TCSs) in both groups. There were significant improvements in scoring AD and other objective measures during the frequent bathing time period vs infrequent bathing; in the group that bathed more frequently, SCORAD (SCORing Atopic Dermatitis) decreased by 21.2 compared with the group that bathed less frequently (95% confidence interval, 14.9-27.6; P<.0001). These findings suggest that more-frequent bathing with immediate moisturization is superior as an acute treatment intervention for improving AD disease severity in comparison to less-frequent bathing with immediate moisturization.²⁰

Expanding Treatment Options

Topical Phosphodiesterase Inhibitors
There are several new and evolving topical therapies in AD. Crisaborole ointment 2% is a steroid-free phosphodiesterase inhibitor approved in 2016 by the US Food and Drug Administration (FDA) for mild to moderate AD in patients aged 2 years and older. A recent multicenter, open-label, single-arm study in 137 infants (CrisADe CARE 1) evaluated the pharmacokinetics and efficacy of crisaborole ointment 2% applied twice daily for 4 weeks in pediatric patients aged 3 months to less than 24 months of age with mild to moderate AD.²¹ The study had 2 cohorts: one with a minimum of 5% body surface area involvement and another (the pharmacokinetic cohort) with a minimum of 35% body surface area involvement. Both cohorts demonstrated similar efficacy data. From baseline to day 29, the mean percentage change in eczema area and severity index (EASI) score was −57.5%, and an investigator global assessment (IGA) score of clear or almost clear with at least a 2-grade improvement was achieved in 30.2% of patients. Crisaborole systemic exposures in infants were comparable with those in patients aged 2 years or older. Patients tolerated crisaborole well, with a 4% rate of burning, which was similar to other studies in children and adults but perhaps lower than seen in clinical practice. Pharmacokinetic studies did not show any remarkable noticeable concern with accumulation of propylene glycol absorption.²¹

Based on the CrisADe CARE 1 study data, in March 2020 the FDA extended the indication of crisaborole ointment 2% from a prior lower age limit of 24 months to approval for use in treating mild to moderate AD in children as young as 3 months, making it the first nonsteroidal topical anti-inflammatory medication to be approved in children younger than 2 years in the United States.

Evolving Topical Therapies

Topical Janus Kinase Inhibitors
Ruxolitinib is a potent inhibitor of Janus kinase 1 (JAK-1) and Janus kinase 2 (JAK-2) and has been developed in topical formulations. In recent phase 3 clinical trials of patients with AD aged 12 years and older with mild to moderate disease (TRuE-AD1 and TRuE-AD2), more than half of the patients treated with either ruxolitinib cream in a 0.75% or 1.5% concentration reached EASI-75 after 8 weeks of treatment.²² Additionally, more patients treated with topical ruxolitinib reached an IGA score of clear to almost clear than patients treated with vehicle at the end of treatment. Thus far, it appears to be very well tolerated, significantly decreases EASI score (P<.0001), and improves overall pruritus.²²

Delgocitinib is a topical pan-JAK inhibitor that blocks several cytokine-signaling cascade pathways. It was first developed and approved in Japan in an ointment formulation for use in patients with AD aged 16 years and older.²³ The efficacy and safety profile of delgocitinib is currently being evaluated in pediatric patients with AD in Japan. In a recent phase 2 clinical study of 103 Japanese patients aged 2 to 15 years with moderate to severe AD, patients were randomized to receive either delgocitinib ointment in 0.25% or 0.5% concentrations or vehicle ointment twice daily for 4 weeks. The proportion of patients with a modified EASI-75 score was 38.2% (13/34) in the 0.25% group and 50.0% (17/34) in the 0.5% group vs 8.6% (3/35) in the placebo group. More patients treated with delgocitinib ointment received an IGA score of clear or almost clear than patients treated with vehicle at the end of treatment. Overall, both delgocitinib groups demonstrated superior improvement in clinical symptoms and signs without notable side effects.²⁴

Tapinarof
Tapinarof is a topical therapeutic aryl hydrocarbon receptor agonist. In a recent phase 2 randomized study of 2 concentrations and 2 frequencies of tapinarof cream vs vehicle in 247 randomized patients aged 12 to 65 years with moderate to severe disease, tapinarof demonstrated greater success with both concentrations than vehicle at all visits beyond week 2.²⁵ Additionally, in patients treated with tapinarof cream 1%, nearly 50% reached an IGA score of clear to almost clear with at least a 2-grade improvement. More than 50% of patients achieved EASI-75 improvement at 12 weeks of treatment with tapinarof cream 1% used daily. These findings suggest that tapinarof may be an efficacious and well-tolerated treatment for both adolescents and adults with AD; however, large confirmation trials are needed to further investigate.²⁵

Systemic Treatments

Oral JAK Inhibitors
Some of the most exciting novel therapies include several oral JAK inhibitors that target different combinations of kinases and have been shown to decrease AD severity and symptoms. Some of these agents have indications in other disease states, such as baricitinib and upadacitinib, which are both FDA approved for the treatment of rheumatoid arthritis, whereas others, such as abrocitinib, have been studied specifically for AD.

Although some agents have only been studied in adults to date, others have included adolescents in their core studies, such as abrocitinib, which received Breakthrough Therapy designation from the FDA for the treatment of patients with moderate to severe AD in February 2018. In recent phase 3 trials of patients aged 12 years and older with moderate to severe AD (JADE MONO-1 and JADE MONO-2), both doses of abrocitinib improved the IGA and EASI-75 outcomes compared with placebo.²⁶ Additional studies will be conducted to further investigate the relative efficacy and safety in patients younger than 18 years.

Biologics
Dupilumab is a fully human monoclonal antibody that inhibits IL-4 and IL-13 signaling without suppressing the immune system. It is approved for use in patients aged 12 years and older with moderate to severe asthma and in adults with chronic rhinosinusitis with nasal polyposis. It is the first biologic to show positive results in the moderate to severe pediatric AD population. There are now extended data available exhibiting sustained benefit in adolescent patients who were continued on dupilumab therapy, evidenced by further improvement in EASI scores at the 1-year mark.²⁷

Recently, dupilumab received approval for use in patients aged 6 to 11 years, making it the first biologic for AD to be approved for use in patients younger than 12 years. The expedited FDA approval was based on the phase 3 results in which the efficacy and safety of dupilumab combined with TCSs were compared to TCSs alone (N=367).²⁸ In this trial, more than twice as many children achieved clear or almost clear skin and more than 4 times as many achieved itch reduction with dupilumab plus TCSs than with TCSs alone. Three-quarters of patients receiving dupilumab at the subsequently approved dosing achieved at least a 75% improvement in overall disease.²⁸ An additional study is being conducted that includes pediatric patients aged 6 months to younger than 6 years (ClinicalTrials.gov Identifier NCT03346434).

Future Directions in Pediatric AD

Our review summarizes only some of the agents under clinical investigation for use in pediatric AD. Early treatment to establish excellent long-term disease control with aggressive topical regimens or with systemic agents may alter the course of AD and influence the development of comorbidities, though this has not yet been shown in clinical studies. The long-term impact of early treatment, along with many other intriguing issues, will be studied more in the near future.

Atopic dermatitis (AD) is a chronic, pruritic, inflammatory skin disease that occurs most frequently in children but also affects many adolescents and adults. There has been a tremendous evolution of knowledge in AD, with insights into pathogenesis, epidemiology, impact of disease, and new therapies. A variety of studies examine the epidemiology of AD and associated comorbidities. The broad developments in disease state research are reflected in new publication numbers of AD citations on PubMed. A PubMed search of articles indexed for MEDLINE at the end of 2010 using the term atopic dermatitis would have shown 965 citations during the preceding 1-year period. In the 1-year period of June 2019 to June 2020, there were more than 2000 articles. The large body of research includes work of great significance in pediatric AD, and in this article we review recent findings that are important in understanding the progress being made in the field.

Epidemiology and Comorbidities

The epidemiology of AD has evolved over the last few decades, with emerging trends and novel insights into the burden of disease.¹ In a recent cross-sectional study on the epidemiology of AD in children aged 6 to 11 years, the 1-year diagnosed AD prevalence estimates worldwide included the following: United States, 10.0%; Canada, 13.3%; the EU5 Countries, 15.5%; Japan, 10.3%; and all countries studied, 12.2%.² Another recent paper that analyzed data from the Fragile Families and Child Wellbeing Study showed that the prevalence and persistence of AD in urban US children was 15.0%.³Although pediatric AD may spontaneously remit over time, disease continuing into adolescence and adulthood is common. Paternoster et al⁴ studied the longitudinal course of AD in children from 2 birth cohort prospective studies, showing distinct AD phenotypes having differing course trajectories over time. Disease subsets included patients with early-onset-persistent and early-onset-late-resolving disease.⁴ Whether phenotyping or subgroup analysis can be used to predict disease course or risk for development of comorbidities is unknown, but it is interesting to consider how such work could influence tailoring of specific therapies to early disease presentation.

Atopic dermatitis poses a serious public health burden owing to its high prevalence, considerable morbidity and disability, increased health care utilization, and cost of care.¹ Recent studies have found notably higher rates of multiple medical and mental health comorbidities in both children and adults with AD, including infections, atopic comorbidities (eg, allergic rhinitis, asthma, food allergies), eye diseases (eg, keratitis, conjunctivitis, keratoconus), and possible cardiovascular diseases and autoimmune disorders.^1,5-9 Allergic comorbidities are quite common in pediatric AD patients.¹⁰ In a recent study examining the efficacy and safety of dupilumab monotherapy in 251 adolescents with moderate to severe inadequately controlled AD, most had comorbid type 2 diseases including asthma (53.6%), food allergies (60.8%), and allergic rhinitis (65.6%).¹¹

Quality of Life/Life Impact of AD

Pediatric AD has a major impact on the quality of life of patients and their families.¹² The well-being and development of children are strongly influenced by the physical and psychosocial health of parents/guardians. Two studies by Ramirez and colleagues^13,14 published in 2019 examined sleep disturbances and exhaustion in mothers of children with AD. Data for the studies came from the Avon Longitudinal Study of Parents and Children. Children with active AD reported worse sleep quality than those without AD, with nearly 50% higher odds of sleep-quality disturbances. Analysis of the cohort data from 11,649 mother-child pairs who were followed up with a time-varying measure of child AD activity and severity as well as self-reported maternal sleep measures repeated at multiple time points for children aged 6 months to 11 years showed that mothers of children with AD reported difficulty falling asleep, subjectively insufficient sleep, and daytime exhaustion throughout the first 11 years of childhood.^13,14 These data suggest that sleep disturbance may be a family affair.

A cross-sectional, real-world study on the burden of AD in children aged 6 to 11 years assessed by self-report demonstrated a substantial and multidimensional impact of AD, including itch, sleep disturbance, skin pain, and health-related quality-of-life impact, as well as comorbidities and school productivity losses. The burden associated with AD was remarkable and increased with disease severity.¹⁵

Drucker et al¹⁶ completed a comprehensive literature review on the burden of AD, summarized as a report for the National Eczema Association. Quality-of-life impact on pediatric patients included high rates of emotional distress; social isolation; depression; limitations in activities due to lesions with fear of triggers; and behavioral problems such as irritability, crying, and sleep disturbance resulting in difficulty performing at school.¹⁶ The psychological impact on children as well as emotional and behavioral difficulties may impact the ability for parents/guardians to implement treatment plans.¹⁷

There is a striking association between mental health disorders and AD in the US pediatric population, with a clear dose-dependent relationship that has been observed between the prevalence of a mental health disorder and the reported severity of the skin disease. Data suggest children with AD may be at increased risk for developing mental health disorders. The National Survey of Children’s Health found statistically significant increases in the likelihood of attention deficit hyperactivity disorder (odds ratio [OR], 1.87), depression (OR, 1.81), anxiety (OR, 1.77), conduct disorder (OR, 1.87), and autism (OR, 3.04).⁶

Evolving Practices and Therapies

Bathing Practices
There has long been much controversy regarding best bathing habits for patients with AD. In a 2009 study, cutaneous hydration was quantified after various bathing and moisturizing regimens.¹⁸ The study showed clear benefits of emollient application on skin hydration, either after bathing or without bathing. Bathing followed by emollient applications did not decrease skin hydration in contrast to bathing without emollient application.¹⁸

There are limited studies evaluating bathing frequency in pediatric patients, and many families receive conflicting information regarding best practice. In one study that surveyed 354 parents, more than 75% of parents/guardians who had seen multiple providers for their child’s AD reported a substantial amount of confusion and frustration from conflicting advice on bathing frequency.¹⁹ Cardona et al²⁰ undertook a randomized clinical trial of frequent bathing and moisturizing vs less-frequent bathing and moisturizing in pediatric patients with AD aged 6 months to 11 years. Patients were divided into 2 groups: 1 being bathed twice daily with immediate moisturizer application and the other being bathed twice weekly followed by moisturization, then a switch to the other method. Patients used standardized topical corticosteroids (TCSs) in both groups. There were significant improvements in scoring AD and other objective measures during the frequent bathing time period vs infrequent bathing; in the group that bathed more frequently, SCORAD (SCORing Atopic Dermatitis) decreased by 21.2 compared with the group that bathed less frequently (95% confidence interval, 14.9-27.6; P<.0001). These findings suggest that more-frequent bathing with immediate moisturization is superior as an acute treatment intervention for improving AD disease severity in comparison to less-frequent bathing with immediate moisturization.²⁰

Expanding Treatment Options

Topical Phosphodiesterase Inhibitors
There are several new and evolving topical therapies in AD. Crisaborole ointment 2% is a steroid-free phosphodiesterase inhibitor approved in 2016 by the US Food and Drug Administration (FDA) for mild to moderate AD in patients aged 2 years and older. A recent multicenter, open-label, single-arm study in 137 infants (CrisADe CARE 1) evaluated the pharmacokinetics and efficacy of crisaborole ointment 2% applied twice daily for 4 weeks in pediatric patients aged 3 months to less than 24 months of age with mild to moderate AD.²¹ The study had 2 cohorts: one with a minimum of 5% body surface area involvement and another (the pharmacokinetic cohort) with a minimum of 35% body surface area involvement. Both cohorts demonstrated similar efficacy data. From baseline to day 29, the mean percentage change in eczema area and severity index (EASI) score was −57.5%, and an investigator global assessment (IGA) score of clear or almost clear with at least a 2-grade improvement was achieved in 30.2% of patients. Crisaborole systemic exposures in infants were comparable with those in patients aged 2 years or older. Patients tolerated crisaborole well, with a 4% rate of burning, which was similar to other studies in children and adults but perhaps lower than seen in clinical practice. Pharmacokinetic studies did not show any remarkable noticeable concern with accumulation of propylene glycol absorption.²¹

Based on the CrisADe CARE 1 study data, in March 2020 the FDA extended the indication of crisaborole ointment 2% from a prior lower age limit of 24 months to approval for use in treating mild to moderate AD in children as young as 3 months, making it the first nonsteroidal topical anti-inflammatory medication to be approved in children younger than 2 years in the United States.

Evolving Topical Therapies

Topical Janus Kinase Inhibitors
Ruxolitinib is a potent inhibitor of Janus kinase 1 (JAK-1) and Janus kinase 2 (JAK-2) and has been developed in topical formulations. In recent phase 3 clinical trials of patients with AD aged 12 years and older with mild to moderate disease (TRuE-AD1 and TRuE-AD2), more than half of the patients treated with either ruxolitinib cream in a 0.75% or 1.5% concentration reached EASI-75 after 8 weeks of treatment.²² Additionally, more patients treated with topical ruxolitinib reached an IGA score of clear to almost clear than patients treated with vehicle at the end of treatment. Thus far, it appears to be very well tolerated, significantly decreases EASI score (P<.0001), and improves overall pruritus.²²

Delgocitinib is a topical pan-JAK inhibitor that blocks several cytokine-signaling cascade pathways. It was first developed and approved in Japan in an ointment formulation for use in patients with AD aged 16 years and older.²³ The efficacy and safety profile of delgocitinib is currently being evaluated in pediatric patients with AD in Japan. In a recent phase 2 clinical study of 103 Japanese patients aged 2 to 15 years with moderate to severe AD, patients were randomized to receive either delgocitinib ointment in 0.25% or 0.5% concentrations or vehicle ointment twice daily for 4 weeks. The proportion of patients with a modified EASI-75 score was 38.2% (13/34) in the 0.25% group and 50.0% (17/34) in the 0.5% group vs 8.6% (3/35) in the placebo group. More patients treated with delgocitinib ointment received an IGA score of clear or almost clear than patients treated with vehicle at the end of treatment. Overall, both delgocitinib groups demonstrated superior improvement in clinical symptoms and signs without notable side effects.²⁴

Tapinarof
Tapinarof is a topical therapeutic aryl hydrocarbon receptor agonist. In a recent phase 2 randomized study of 2 concentrations and 2 frequencies of tapinarof cream vs vehicle in 247 randomized patients aged 12 to 65 years with moderate to severe disease, tapinarof demonstrated greater success with both concentrations than vehicle at all visits beyond week 2.²⁵ Additionally, in patients treated with tapinarof cream 1%, nearly 50% reached an IGA score of clear to almost clear with at least a 2-grade improvement. More than 50% of patients achieved EASI-75 improvement at 12 weeks of treatment with tapinarof cream 1% used daily. These findings suggest that tapinarof may be an efficacious and well-tolerated treatment for both adolescents and adults with AD; however, large confirmation trials are needed to further investigate.²⁵

Systemic Treatments

Oral JAK Inhibitors
Some of the most exciting novel therapies include several oral JAK inhibitors that target different combinations of kinases and have been shown to decrease AD severity and symptoms. Some of these agents have indications in other disease states, such as baricitinib and upadacitinib, which are both FDA approved for the treatment of rheumatoid arthritis, whereas others, such as abrocitinib, have been studied specifically for AD.

Although some agents have only been studied in adults to date, others have included adolescents in their core studies, such as abrocitinib, which received Breakthrough Therapy designation from the FDA for the treatment of patients with moderate to severe AD in February 2018. In recent phase 3 trials of patients aged 12 years and older with moderate to severe AD (JADE MONO-1 and JADE MONO-2), both doses of abrocitinib improved the IGA and EASI-75 outcomes compared with placebo.²⁶ Additional studies will be conducted to further investigate the relative efficacy and safety in patients younger than 18 years.

Biologics
Dupilumab is a fully human monoclonal antibody that inhibits IL-4 and IL-13 signaling without suppressing the immune system. It is approved for use in patients aged 12 years and older with moderate to severe asthma and in adults with chronic rhinosinusitis with nasal polyposis. It is the first biologic to show positive results in the moderate to severe pediatric AD population. There are now extended data available exhibiting sustained benefit in adolescent patients who were continued on dupilumab therapy, evidenced by further improvement in EASI scores at the 1-year mark.²⁷

Recently, dupilumab received approval for use in patients aged 6 to 11 years, making it the first biologic for AD to be approved for use in patients younger than 12 years. The expedited FDA approval was based on the phase 3 results in which the efficacy and safety of dupilumab combined with TCSs were compared to TCSs alone (N=367).²⁸ In this trial, more than twice as many children achieved clear or almost clear skin and more than 4 times as many achieved itch reduction with dupilumab plus TCSs than with TCSs alone. Three-quarters of patients receiving dupilumab at the subsequently approved dosing achieved at least a 75% improvement in overall disease.²⁸ An additional study is being conducted that includes pediatric patients aged 6 months to younger than 6 years (ClinicalTrials.gov Identifier NCT03346434).

Future Directions in Pediatric AD

Our review summarizes only some of the agents under clinical investigation for use in pediatric AD. Early treatment to establish excellent long-term disease control with aggressive topical regimens or with systemic agents may alter the course of AD and influence the development of comorbidities, though this has not yet been shown in clinical studies. The long-term impact of early treatment, along with many other intriguing issues, will be studied more in the near future.

Atopic dermatitis (AD) is a chronic, pruritic, inflammatory skin disease that occurs most frequently in children but also affects many adolescents and adults. There has been a tremendous evolution of knowledge in AD, with insights into pathogenesis, epidemiology, impact of disease, and new therapies. A variety of studies examine the epidemiology of AD and associated comorbidities. The broad developments in disease state research are reflected in new publication numbers of AD citations on PubMed. A PubMed search of articles indexed for MEDLINE at the end of 2010 using the term atopic dermatitis would have shown 965 citations during the preceding 1-year period. In the 1-year period of June 2019 to June 2020, there were more than 2000 articles. The large body of research includes work of great significance in pediatric AD, and in this article we review recent findings that are important in understanding the progress being made in the field.

Epidemiology and Comorbidities

The epidemiology of AD has evolved over the last few decades, with emerging trends and novel insights into the burden of disease.¹ In a recent cross-sectional study on the epidemiology of AD in children aged 6 to 11 years, the 1-year diagnosed AD prevalence estimates worldwide included the following: United States, 10.0%; Canada, 13.3%; the EU5 Countries, 15.5%; Japan, 10.3%; and all countries studied, 12.2%.² Another recent paper that analyzed data from the Fragile Families and Child Wellbeing Study showed that the prevalence and persistence of AD in urban US children was 15.0%.³Although pediatric AD may spontaneously remit over time, disease continuing into adolescence and adulthood is common. Paternoster et al⁴ studied the longitudinal course of AD in children from 2 birth cohort prospective studies, showing distinct AD phenotypes having differing course trajectories over time. Disease subsets included patients with early-onset-persistent and early-onset-late-resolving disease.⁴ Whether phenotyping or subgroup analysis can be used to predict disease course or risk for development of comorbidities is unknown, but it is interesting to consider how such work could influence tailoring of specific therapies to early disease presentation.

Atopic dermatitis poses a serious public health burden owing to its high prevalence, considerable morbidity and disability, increased health care utilization, and cost of care.¹ Recent studies have found notably higher rates of multiple medical and mental health comorbidities in both children and adults with AD, including infections, atopic comorbidities (eg, allergic rhinitis, asthma, food allergies), eye diseases (eg, keratitis, conjunctivitis, keratoconus), and possible cardiovascular diseases and autoimmune disorders.^1,5-9 Allergic comorbidities are quite common in pediatric AD patients.¹⁰ In a recent study examining the efficacy and safety of dupilumab monotherapy in 251 adolescents with moderate to severe inadequately controlled AD, most had comorbid type 2 diseases including asthma (53.6%), food allergies (60.8%), and allergic rhinitis (65.6%).¹¹

Quality of Life/Life Impact of AD

Pediatric AD has a major impact on the quality of life of patients and their families.¹² The well-being and development of children are strongly influenced by the physical and psychosocial health of parents/guardians. Two studies by Ramirez and colleagues^13,14 published in 2019 examined sleep disturbances and exhaustion in mothers of children with AD. Data for the studies came from the Avon Longitudinal Study of Parents and Children. Children with active AD reported worse sleep quality than those without AD, with nearly 50% higher odds of sleep-quality disturbances. Analysis of the cohort data from 11,649 mother-child pairs who were followed up with a time-varying measure of child AD activity and severity as well as self-reported maternal sleep measures repeated at multiple time points for children aged 6 months to 11 years showed that mothers of children with AD reported difficulty falling asleep, subjectively insufficient sleep, and daytime exhaustion throughout the first 11 years of childhood.^13,14 These data suggest that sleep disturbance may be a family affair.

A cross-sectional, real-world study on the burden of AD in children aged 6 to 11 years assessed by self-report demonstrated a substantial and multidimensional impact of AD, including itch, sleep disturbance, skin pain, and health-related quality-of-life impact, as well as comorbidities and school productivity losses. The burden associated with AD was remarkable and increased with disease severity.¹⁵

Drucker et al¹⁶ completed a comprehensive literature review on the burden of AD, summarized as a report for the National Eczema Association. Quality-of-life impact on pediatric patients included high rates of emotional distress; social isolation; depression; limitations in activities due to lesions with fear of triggers; and behavioral problems such as irritability, crying, and sleep disturbance resulting in difficulty performing at school.¹⁶ The psychological impact on children as well as emotional and behavioral difficulties may impact the ability for parents/guardians to implement treatment plans.¹⁷

There is a striking association between mental health disorders and AD in the US pediatric population, with a clear dose-dependent relationship that has been observed between the prevalence of a mental health disorder and the reported severity of the skin disease. Data suggest children with AD may be at increased risk for developing mental health disorders. The National Survey of Children’s Health found statistically significant increases in the likelihood of attention deficit hyperactivity disorder (odds ratio [OR], 1.87), depression (OR, 1.81), anxiety (OR, 1.77), conduct disorder (OR, 1.87), and autism (OR, 3.04).⁶

Evolving Practices and Therapies

Bathing Practices
There has long been much controversy regarding best bathing habits for patients with AD. In a 2009 study, cutaneous hydration was quantified after various bathing and moisturizing regimens.¹⁸ The study showed clear benefits of emollient application on skin hydration, either after bathing or without bathing. Bathing followed by emollient applications did not decrease skin hydration in contrast to bathing without emollient application.¹⁸

There are limited studies evaluating bathing frequency in pediatric patients, and many families receive conflicting information regarding best practice. In one study that surveyed 354 parents, more than 75% of parents/guardians who had seen multiple providers for their child’s AD reported a substantial amount of confusion and frustration from conflicting advice on bathing frequency.¹⁹ Cardona et al²⁰ undertook a randomized clinical trial of frequent bathing and moisturizing vs less-frequent bathing and moisturizing in pediatric patients with AD aged 6 months to 11 years. Patients were divided into 2 groups: 1 being bathed twice daily with immediate moisturizer application and the other being bathed twice weekly followed by moisturization, then a switch to the other method. Patients used standardized topical corticosteroids (TCSs) in both groups. There were significant improvements in scoring AD and other objective measures during the frequent bathing time period vs infrequent bathing; in the group that bathed more frequently, SCORAD (SCORing Atopic Dermatitis) decreased by 21.2 compared with the group that bathed less frequently (95% confidence interval, 14.9-27.6; P<.0001). These findings suggest that more-frequent bathing with immediate moisturization is superior as an acute treatment intervention for improving AD disease severity in comparison to less-frequent bathing with immediate moisturization.²⁰

Expanding Treatment Options

Topical Phosphodiesterase Inhibitors
There are several new and evolving topical therapies in AD. Crisaborole ointment 2% is a steroid-free phosphodiesterase inhibitor approved in 2016 by the US Food and Drug Administration (FDA) for mild to moderate AD in patients aged 2 years and older. A recent multicenter, open-label, single-arm study in 137 infants (CrisADe CARE 1) evaluated the pharmacokinetics and efficacy of crisaborole ointment 2% applied twice daily for 4 weeks in pediatric patients aged 3 months to less than 24 months of age with mild to moderate AD.²¹ The study had 2 cohorts: one with a minimum of 5% body surface area involvement and another (the pharmacokinetic cohort) with a minimum of 35% body surface area involvement. Both cohorts demonstrated similar efficacy data. From baseline to day 29, the mean percentage change in eczema area and severity index (EASI) score was −57.5%, and an investigator global assessment (IGA) score of clear or almost clear with at least a 2-grade improvement was achieved in 30.2% of patients. Crisaborole systemic exposures in infants were comparable with those in patients aged 2 years or older. Patients tolerated crisaborole well, with a 4% rate of burning, which was similar to other studies in children and adults but perhaps lower than seen in clinical practice. Pharmacokinetic studies did not show any remarkable noticeable concern with accumulation of propylene glycol absorption.²¹

Based on the CrisADe CARE 1 study data, in March 2020 the FDA extended the indication of crisaborole ointment 2% from a prior lower age limit of 24 months to approval for use in treating mild to moderate AD in children as young as 3 months, making it the first nonsteroidal topical anti-inflammatory medication to be approved in children younger than 2 years in the United States.

Evolving Topical Therapies

Topical Janus Kinase Inhibitors
Ruxolitinib is a potent inhibitor of Janus kinase 1 (JAK-1) and Janus kinase 2 (JAK-2) and has been developed in topical formulations. In recent phase 3 clinical trials of patients with AD aged 12 years and older with mild to moderate disease (TRuE-AD1 and TRuE-AD2), more than half of the patients treated with either ruxolitinib cream in a 0.75% or 1.5% concentration reached EASI-75 after 8 weeks of treatment.²² Additionally, more patients treated with topical ruxolitinib reached an IGA score of clear to almost clear than patients treated with vehicle at the end of treatment. Thus far, it appears to be very well tolerated, significantly decreases EASI score (P<.0001), and improves overall pruritus.²²

Delgocitinib is a topical pan-JAK inhibitor that blocks several cytokine-signaling cascade pathways. It was first developed and approved in Japan in an ointment formulation for use in patients with AD aged 16 years and older.²³ The efficacy and safety profile of delgocitinib is currently being evaluated in pediatric patients with AD in Japan. In a recent phase 2 clinical study of 103 Japanese patients aged 2 to 15 years with moderate to severe AD, patients were randomized to receive either delgocitinib ointment in 0.25% or 0.5% concentrations or vehicle ointment twice daily for 4 weeks. The proportion of patients with a modified EASI-75 score was 38.2% (13/34) in the 0.25% group and 50.0% (17/34) in the 0.5% group vs 8.6% (3/35) in the placebo group. More patients treated with delgocitinib ointment received an IGA score of clear or almost clear than patients treated with vehicle at the end of treatment. Overall, both delgocitinib groups demonstrated superior improvement in clinical symptoms and signs without notable side effects.²⁴

Tapinarof
Tapinarof is a topical therapeutic aryl hydrocarbon receptor agonist. In a recent phase 2 randomized study of 2 concentrations and 2 frequencies of tapinarof cream vs vehicle in 247 randomized patients aged 12 to 65 years with moderate to severe disease, tapinarof demonstrated greater success with both concentrations than vehicle at all visits beyond week 2.²⁵ Additionally, in patients treated with tapinarof cream 1%, nearly 50% reached an IGA score of clear to almost clear with at least a 2-grade improvement. More than 50% of patients achieved EASI-75 improvement at 12 weeks of treatment with tapinarof cream 1% used daily. These findings suggest that tapinarof may be an efficacious and well-tolerated treatment for both adolescents and adults with AD; however, large confirmation trials are needed to further investigate.²⁵

Systemic Treatments

Oral JAK Inhibitors
Some of the most exciting novel therapies include several oral JAK inhibitors that target different combinations of kinases and have been shown to decrease AD severity and symptoms. Some of these agents have indications in other disease states, such as baricitinib and upadacitinib, which are both FDA approved for the treatment of rheumatoid arthritis, whereas others, such as abrocitinib, have been studied specifically for AD.

Although some agents have only been studied in adults to date, others have included adolescents in their core studies, such as abrocitinib, which received Breakthrough Therapy designation from the FDA for the treatment of patients with moderate to severe AD in February 2018. In recent phase 3 trials of patients aged 12 years and older with moderate to severe AD (JADE MONO-1 and JADE MONO-2), both doses of abrocitinib improved the IGA and EASI-75 outcomes compared with placebo.²⁶ Additional studies will be conducted to further investigate the relative efficacy and safety in patients younger than 18 years.

Biologics
Dupilumab is a fully human monoclonal antibody that inhibits IL-4 and IL-13 signaling without suppressing the immune system. It is approved for use in patients aged 12 years and older with moderate to severe asthma and in adults with chronic rhinosinusitis with nasal polyposis. It is the first biologic to show positive results in the moderate to severe pediatric AD population. There are now extended data available exhibiting sustained benefit in adolescent patients who were continued on dupilumab therapy, evidenced by further improvement in EASI scores at the 1-year mark.²⁷

Recently, dupilumab received approval for use in patients aged 6 to 11 years, making it the first biologic for AD to be approved for use in patients younger than 12 years. The expedited FDA approval was based on the phase 3 results in which the efficacy and safety of dupilumab combined with TCSs were compared to TCSs alone (N=367).²⁸ In this trial, more than twice as many children achieved clear or almost clear skin and more than 4 times as many achieved itch reduction with dupilumab plus TCSs than with TCSs alone. Three-quarters of patients receiving dupilumab at the subsequently approved dosing achieved at least a 75% improvement in overall disease.²⁸ An additional study is being conducted that includes pediatric patients aged 6 months to younger than 6 years (ClinicalTrials.gov Identifier NCT03346434).

Future Directions in Pediatric AD

Our review summarizes only some of the agents under clinical investigation for use in pediatric AD. Early treatment to establish excellent long-term disease control with aggressive topical regimens or with systemic agents may alter the course of AD and influence the development of comorbidities, though this has not yet been shown in clinical studies. The long-term impact of early treatment, along with many other intriguing issues, will be studied more in the near future.

Pityriasis rubra pilaris (PRP) is the name given to a heterogeneous group of rare inflammatory papulosquamous dermatoses. There are six sub-types that can present with various skin findings, however, the cardinal features across sub-types include well-defined, red-orange hued plaques with varying scale, palmoplantar keratoderma, and follicular keratosis. In the more generalized subtypes, there is a characteristic feature of intervening areas of unaffected skin often referred to as “islands of sparing.” The plaques may cover the entire body or just parts of the body such as the elbows and knees, palms and soles. Lesions are generally asymptomatic; occasionally patients complain of mild pruritus. 

Photos courtesy of Robert Silverman, MD

The etiology and pathophysiology of this group of disorders is not well understood. However, there are several hypotheses including dysfunction in vitamin A metabolism, autoimmune dysregulation, as well as environmental and immunologic triggers such as infection and ultraviolet exposure. Although most cases are sporadic, genetics do seem to play a role in the development of some cases. Caspase recruitment domain-containing protein 14 (CARD14) mutations are seen in familial PRP, and occasionally in patients with sporadic PRP, with gain of function mutations. Interestingly, CARD14 mutations are also associated with psoriasis in some individuals.¹ The type-VI PRP variant has been associated with HIV, although this is incredibly rare in pediatrics.²

PRP shows significant clinical diversity, with six subtypes defined by age of onset, distribution, and appearance of lesions, and presence of HIV. This includes type I (classical adult onset), type II (atypical adult onset), type III (classical juvenile onset), type IV (circumscribed juvenile onset), type V (atypical juvenile onset), and type VI (HIV-associated). As mentioned earlier, shared features that appear across subtypes in variable degrees include red-orange papules and plaques, hyperkeratotic follicular papules, and palmoplantar hyperkeratosis.

Of the six subtypes, type III, IV, and V occur in the pediatric population. Type III, classic juvenile PRP, typically occurs within the first 2 years of life or in adolescence. Only 10% of cases fall into this category. It shares similar features to type I PRP including red-orange plaques; islands of sparing, perifollicular hyperkeratotic papules; waxy palmoplantar keratoderma; and the distribution of affected skin is more diffuse overall. While some children clear within a few years, more recent studies stress a more prolonged course similar to the type IV variant.²

Type-IV PRP, also known as circumscribed juvenile PRP, is a focal variant, usually seen in prepubertal children and making up 25% of total cases. Clinically, these patients tend to have sharply demarcated grouped erythematous, follicular papules on the elbows, knees and over bony prominences.²

Type-V PRP is an atypical generalized juvenile variant which affects 5% of patients. It is a non-remitting hereditary condition with classic characteristics similar to type III with additional scleroderma-like changes involving the palms and soles.²

Diagnosis of PRP is based on clinical recognition and biopsy can be important to secure a diagnosis.

PRP, in many cases is self-limited and asymptomatic, and therefore does not necessarily require treatment. In other patients treatment can be challenging, and referral to a pediatric dermatology specialist is reasonable. Most practitioners recommend combination therapy with topical agents (emollients, topical corticosteroids, tazarotene, topical calcineurin inhibitors, and keratolytic agents such as urea, salicylic acid, or alpha-hydroxy acids) for symptomatic management and systemic therapies (methotrexate, isotretinoin) aimed at reducing inflammation. There is some data that CARD14-associated PRP can respond well to targeted biologic therapies.¹

The subtypes of PRP can present in a myriad of ways and often the disease is misdiagnosed. Depending on the particular subtype and findings present, the differential can vary considerably. Commonly, physicians need to consider: psoriasis, seborrheic dermatitis, atopic dermatitis, ichthyoses, and other conditions which can cause erythroderma.³ The characteristic red-orange color and variable associated edema helps to distinguish keratoderma of PRP from psoriasis, atopic dermatitis, ichthyosis, and hereditary palmoplantar keratoderma. Scalp involvement of PRP should be differentiated from the waxy scale of seborrheic dermatitis and the well demarcated silvery scale of psoriasis. History alone may assist in distinguishing PRP from other major causes of generalized erythroderma, although biopsy is warranted in these cases.
 

Dr. Eichenfield is chief of pediatric and adolescent dermatology at Rady Children’s Hospital–San Diego. He is vice chair of the department of dermatology and professor of dermatology and pediatrics at the University of California, San Diego. Dr. Tracy is a research fellow in pediatric dermatology at Rady Children’s Hospital-San Diego and the University of California, San Diego. They have no relevant financial disclosures. Email them at [email protected].

References

1. J Am Acad Dermatol. 2018 Sep;79(3):487-94.

2. “Pityriasis Rubra Pilaris” (Treasure Island, Fla.: StatPearls Publishing, July 20, 2019). 3. JAMA Dermatol. 2016 Jun 1;152(6):670-5.

Pityriasis rubra pilaris (PRP) is the name given to a heterogeneous group of rare inflammatory papulosquamous dermatoses. There are six sub-types that can present with various skin findings, however, the cardinal features across sub-types include well-defined, red-orange hued plaques with varying scale, palmoplantar keratoderma, and follicular keratosis. In the more generalized subtypes, there is a characteristic feature of intervening areas of unaffected skin often referred to as “islands of sparing.” The plaques may cover the entire body or just parts of the body such as the elbows and knees, palms and soles. Lesions are generally asymptomatic; occasionally patients complain of mild pruritus. 

Photos courtesy of Robert Silverman, MD

The etiology and pathophysiology of this group of disorders is not well understood. However, there are several hypotheses including dysfunction in vitamin A metabolism, autoimmune dysregulation, as well as environmental and immunologic triggers such as infection and ultraviolet exposure. Although most cases are sporadic, genetics do seem to play a role in the development of some cases. Caspase recruitment domain-containing protein 14 (CARD14) mutations are seen in familial PRP, and occasionally in patients with sporadic PRP, with gain of function mutations. Interestingly, CARD14 mutations are also associated with psoriasis in some individuals.¹ The type-VI PRP variant has been associated with HIV, although this is incredibly rare in pediatrics.²

PRP shows significant clinical diversity, with six subtypes defined by age of onset, distribution, and appearance of lesions, and presence of HIV. This includes type I (classical adult onset), type II (atypical adult onset), type III (classical juvenile onset), type IV (circumscribed juvenile onset), type V (atypical juvenile onset), and type VI (HIV-associated). As mentioned earlier, shared features that appear across subtypes in variable degrees include red-orange papules and plaques, hyperkeratotic follicular papules, and palmoplantar hyperkeratosis.

Of the six subtypes, type III, IV, and V occur in the pediatric population. Type III, classic juvenile PRP, typically occurs within the first 2 years of life or in adolescence. Only 10% of cases fall into this category. It shares similar features to type I PRP including red-orange plaques; islands of sparing, perifollicular hyperkeratotic papules; waxy palmoplantar keratoderma; and the distribution of affected skin is more diffuse overall. While some children clear within a few years, more recent studies stress a more prolonged course similar to the type IV variant.²

Type-IV PRP, also known as circumscribed juvenile PRP, is a focal variant, usually seen in prepubertal children and making up 25% of total cases. Clinically, these patients tend to have sharply demarcated grouped erythematous, follicular papules on the elbows, knees and over bony prominences.²

Type-V PRP is an atypical generalized juvenile variant which affects 5% of patients. It is a non-remitting hereditary condition with classic characteristics similar to type III with additional scleroderma-like changes involving the palms and soles.²

Diagnosis of PRP is based on clinical recognition and biopsy can be important to secure a diagnosis.

PRP, in many cases is self-limited and asymptomatic, and therefore does not necessarily require treatment. In other patients treatment can be challenging, and referral to a pediatric dermatology specialist is reasonable. Most practitioners recommend combination therapy with topical agents (emollients, topical corticosteroids, tazarotene, topical calcineurin inhibitors, and keratolytic agents such as urea, salicylic acid, or alpha-hydroxy acids) for symptomatic management and systemic therapies (methotrexate, isotretinoin) aimed at reducing inflammation. There is some data that CARD14-associated PRP can respond well to targeted biologic therapies.¹

The subtypes of PRP can present in a myriad of ways and often the disease is misdiagnosed. Depending on the particular subtype and findings present, the differential can vary considerably. Commonly, physicians need to consider: psoriasis, seborrheic dermatitis, atopic dermatitis, ichthyoses, and other conditions which can cause erythroderma.³ The characteristic red-orange color and variable associated edema helps to distinguish keratoderma of PRP from psoriasis, atopic dermatitis, ichthyosis, and hereditary palmoplantar keratoderma. Scalp involvement of PRP should be differentiated from the waxy scale of seborrheic dermatitis and the well demarcated silvery scale of psoriasis. History alone may assist in distinguishing PRP from other major causes of generalized erythroderma, although biopsy is warranted in these cases.
 

Dr. Eichenfield is chief of pediatric and adolescent dermatology at Rady Children’s Hospital–San Diego. He is vice chair of the department of dermatology and professor of dermatology and pediatrics at the University of California, San Diego. Dr. Tracy is a research fellow in pediatric dermatology at Rady Children’s Hospital-San Diego and the University of California, San Diego. They have no relevant financial disclosures. Email them at [email protected].

References

1. J Am Acad Dermatol. 2018 Sep;79(3):487-94.

2. “Pityriasis Rubra Pilaris” (Treasure Island, Fla.: StatPearls Publishing, July 20, 2019). 3. JAMA Dermatol. 2016 Jun 1;152(6):670-5.

Pityriasis rubra pilaris (PRP) is the name given to a heterogeneous group of rare inflammatory papulosquamous dermatoses. There are six sub-types that can present with various skin findings, however, the cardinal features across sub-types include well-defined, red-orange hued plaques with varying scale, palmoplantar keratoderma, and follicular keratosis. In the more generalized subtypes, there is a characteristic feature of intervening areas of unaffected skin often referred to as “islands of sparing.” The plaques may cover the entire body or just parts of the body such as the elbows and knees, palms and soles. Lesions are generally asymptomatic; occasionally patients complain of mild pruritus. 

Photos courtesy of Robert Silverman, MD

The etiology and pathophysiology of this group of disorders is not well understood. However, there are several hypotheses including dysfunction in vitamin A metabolism, autoimmune dysregulation, as well as environmental and immunologic triggers such as infection and ultraviolet exposure. Although most cases are sporadic, genetics do seem to play a role in the development of some cases. Caspase recruitment domain-containing protein 14 (CARD14) mutations are seen in familial PRP, and occasionally in patients with sporadic PRP, with gain of function mutations. Interestingly, CARD14 mutations are also associated with psoriasis in some individuals.¹ The type-VI PRP variant has been associated with HIV, although this is incredibly rare in pediatrics.²

PRP shows significant clinical diversity, with six subtypes defined by age of onset, distribution, and appearance of lesions, and presence of HIV. This includes type I (classical adult onset), type II (atypical adult onset), type III (classical juvenile onset), type IV (circumscribed juvenile onset), type V (atypical juvenile onset), and type VI (HIV-associated). As mentioned earlier, shared features that appear across subtypes in variable degrees include red-orange papules and plaques, hyperkeratotic follicular papules, and palmoplantar hyperkeratosis.

Of the six subtypes, type III, IV, and V occur in the pediatric population. Type III, classic juvenile PRP, typically occurs within the first 2 years of life or in adolescence. Only 10% of cases fall into this category. It shares similar features to type I PRP including red-orange plaques; islands of sparing, perifollicular hyperkeratotic papules; waxy palmoplantar keratoderma; and the distribution of affected skin is more diffuse overall. While some children clear within a few years, more recent studies stress a more prolonged course similar to the type IV variant.²

Type-IV PRP, also known as circumscribed juvenile PRP, is a focal variant, usually seen in prepubertal children and making up 25% of total cases. Clinically, these patients tend to have sharply demarcated grouped erythematous, follicular papules on the elbows, knees and over bony prominences.²

Type-V PRP is an atypical generalized juvenile variant which affects 5% of patients. It is a non-remitting hereditary condition with classic characteristics similar to type III with additional scleroderma-like changes involving the palms and soles.²

Diagnosis of PRP is based on clinical recognition and biopsy can be important to secure a diagnosis.

PRP, in many cases is self-limited and asymptomatic, and therefore does not necessarily require treatment. In other patients treatment can be challenging, and referral to a pediatric dermatology specialist is reasonable. Most practitioners recommend combination therapy with topical agents (emollients, topical corticosteroids, tazarotene, topical calcineurin inhibitors, and keratolytic agents such as urea, salicylic acid, or alpha-hydroxy acids) for symptomatic management and systemic therapies (methotrexate, isotretinoin) aimed at reducing inflammation. There is some data that CARD14-associated PRP can respond well to targeted biologic therapies.¹

The subtypes of PRP can present in a myriad of ways and often the disease is misdiagnosed. Depending on the particular subtype and findings present, the differential can vary considerably. Commonly, physicians need to consider: psoriasis, seborrheic dermatitis, atopic dermatitis, ichthyoses, and other conditions which can cause erythroderma.³ The characteristic red-orange color and variable associated edema helps to distinguish keratoderma of PRP from psoriasis, atopic dermatitis, ichthyosis, and hereditary palmoplantar keratoderma. Scalp involvement of PRP should be differentiated from the waxy scale of seborrheic dermatitis and the well demarcated silvery scale of psoriasis. History alone may assist in distinguishing PRP from other major causes of generalized erythroderma, although biopsy is warranted in these cases.
 

Dr. Eichenfield is chief of pediatric and adolescent dermatology at Rady Children’s Hospital–San Diego. He is vice chair of the department of dermatology and professor of dermatology and pediatrics at the University of California, San Diego. Dr. Tracy is a research fellow in pediatric dermatology at Rady Children’s Hospital-San Diego and the University of California, San Diego. They have no relevant financial disclosures. Email them at [email protected].

References

1. J Am Acad Dermatol. 2018 Sep;79(3):487-94.

2. “Pityriasis Rubra Pilaris” (Treasure Island, Fla.: StatPearls Publishing, July 20, 2019). 3. JAMA Dermatol. 2016 Jun 1;152(6):670-5.

Tumor necrosis factor–alpha (TNF-alpha) inhibitors are therapeutic agents used to treat a variety of inflammatory conditions such as rheumatoid arthritis and inflammatory bowel disease, as well as psoriasis of the skin (PSO) and psoriatic arthritis. Paradoxically, some individuals report new onset of psoriasiform lesions with treatment with TNF-alpha inhibitors for other conditions. In a 2017 systematic review, there were 216 reported cases of new-onset TNF-alpha inhibitor–induced psoriasis, with an estimated rate of 1 per 1,000. The cases thus far have had a wide range of presentations, the most common being plaque psoriasis, scalp psoriasis, as well as palmoplantar pustular psoriasis.¹

Courtesy Dr. Lawrence F. Eichenfield

A retrospective chart review study at Mayo clinic published in 2017 evaluated children younger than 19 years seen in 2003-2015 who developed new-onset or recurrent PSO with a history of inflammatory bowel disease being treated with anti-TNF-alpha therapy. The review showed variable latency in the development of PSO in these patients, although it typically occurred during inflammatory bowel disease remission.² It is unclear whether there is an association between a personal or family history of psoriasis and development of these lesions.

TNF-alpha, interleukin (IL)–17) and interferon-alpha (IFN-alpha) are main cytokines that contribute to the development of psoriasis. The mechanism of action for paradoxical PSO/psoriasis in patients treated with anti-TNF is not clearly understood; however, many hypotheses are based on an imbalance between TNF-alpha and interferon-alpha – more specifically, an increased production of interferon-alpha. TNF-alpha inhibits the activity of plasmacytoid dendritic cells which are key producers of IFN-alpha. Because of this blockade, there is unopposed IFN-alpha production. Interferon-alpha allows for the expression of chemokines such as CXCR3, which favor T cells homing to the skin. IFN-alpha also stimulates and activates T cells to produce TNF-alpha and IL-17, which in turn sustains inflammatory mechanisms and allows for the development of psoriatic lesions.3

Courtesy Dr. Lawrence F. Eichenfield

There are no universal management guidelines. Most of these patients’ treatment plans mirror standard psoriasis therapies while the main question remains the decision to continue the same anti-TNF therapy, change anti-TNF agents, or entirely switch classes of biologic or other systemic therapy. This decision in management requires several considerations: treatability of TNF-alpha inhibitor-induced psoriasis, the severity of background disease (i.e., rheumatoid arthritis, inflammatory bowel disease, other systemic condition), and whether the underlying disease is well controlled on current therapy, as well as the consideration of possible loss in efficacy if a drug is discontinued and then restarted at a later date.⁴

A reasonable initial approach in patients with well-controlled underlying disease and mild skin eruption is to continue anti-TNF therapy and manage skin topically with topical corticosteroids and/or phototherapy. In patients that either do not have well-controlled underlying disease or moderate skin involvement, changing to an alternative anti-TNF or other agent may be reasonable, and requires coordinated care with involved specialists. In the 2017 pediatric review mentioned previously, nearly half of the patients required a change in their initial anti-TNF-alpha agent despite conventional skin-directed therapies, and one-third of patients discontinued all anti-TNF-alpha therapy because of PSO.²

The psoriasiform papulosquamous features of this case along with the history suggests the diagnosis. Pityriasis rosea would be highly atypical on the feet and with the duration of findings. Lichen planus and atopic dermatitis morphology are inconsistent with this eruption, and coxsackie viral infection would have a shorter course.

Dr. Tracy is a research fellow in pediatric dermatology at Rady Children’s Hospital–San Diego and the University of California, San Diego. Dr. Eichenfield is chief of pediatric and adolescent dermatology at Rady Children’s Hospital–San Diego. He is vice chair of the department of dermatology and professor of dermatology and pediatrics at the University of California, San Diego. Email them at [email protected].

References

1. J Am Acad Dermatol. 2017 Feb;76(2):334-41.

2. Pediatr Dermatol. 2017 May;34(3):253-60.

3. RMD Open. 2016 Jul 15;2(2):e000239.

4. J Psoriasis Psoriatic Arthritis. 2019 Apr;4(2):70-80.

Tumor necrosis factor–alpha (TNF-alpha) inhibitors are therapeutic agents used to treat a variety of inflammatory conditions such as rheumatoid arthritis and inflammatory bowel disease, as well as psoriasis of the skin (PSO) and psoriatic arthritis. Paradoxically, some individuals report new onset of psoriasiform lesions with treatment with TNF-alpha inhibitors for other conditions. In a 2017 systematic review, there were 216 reported cases of new-onset TNF-alpha inhibitor–induced psoriasis, with an estimated rate of 1 per 1,000. The cases thus far have had a wide range of presentations, the most common being plaque psoriasis, scalp psoriasis, as well as palmoplantar pustular psoriasis.¹

Courtesy Dr. Lawrence F. Eichenfield

A retrospective chart review study at Mayo clinic published in 2017 evaluated children younger than 19 years seen in 2003-2015 who developed new-onset or recurrent PSO with a history of inflammatory bowel disease being treated with anti-TNF-alpha therapy. The review showed variable latency in the development of PSO in these patients, although it typically occurred during inflammatory bowel disease remission.² It is unclear whether there is an association between a personal or family history of psoriasis and development of these lesions.

TNF-alpha, interleukin (IL)–17) and interferon-alpha (IFN-alpha) are main cytokines that contribute to the development of psoriasis. The mechanism of action for paradoxical PSO/psoriasis in patients treated with anti-TNF is not clearly understood; however, many hypotheses are based on an imbalance between TNF-alpha and interferon-alpha – more specifically, an increased production of interferon-alpha. TNF-alpha inhibits the activity of plasmacytoid dendritic cells which are key producers of IFN-alpha. Because of this blockade, there is unopposed IFN-alpha production. Interferon-alpha allows for the expression of chemokines such as CXCR3, which favor T cells homing to the skin. IFN-alpha also stimulates and activates T cells to produce TNF-alpha and IL-17, which in turn sustains inflammatory mechanisms and allows for the development of psoriatic lesions.3

Courtesy Dr. Lawrence F. Eichenfield

There are no universal management guidelines. Most of these patients’ treatment plans mirror standard psoriasis therapies while the main question remains the decision to continue the same anti-TNF therapy, change anti-TNF agents, or entirely switch classes of biologic or other systemic therapy. This decision in management requires several considerations: treatability of TNF-alpha inhibitor-induced psoriasis, the severity of background disease (i.e., rheumatoid arthritis, inflammatory bowel disease, other systemic condition), and whether the underlying disease is well controlled on current therapy, as well as the consideration of possible loss in efficacy if a drug is discontinued and then restarted at a later date.⁴

A reasonable initial approach in patients with well-controlled underlying disease and mild skin eruption is to continue anti-TNF therapy and manage skin topically with topical corticosteroids and/or phototherapy. In patients that either do not have well-controlled underlying disease or moderate skin involvement, changing to an alternative anti-TNF or other agent may be reasonable, and requires coordinated care with involved specialists. In the 2017 pediatric review mentioned previously, nearly half of the patients required a change in their initial anti-TNF-alpha agent despite conventional skin-directed therapies, and one-third of patients discontinued all anti-TNF-alpha therapy because of PSO.²

The psoriasiform papulosquamous features of this case along with the history suggests the diagnosis. Pityriasis rosea would be highly atypical on the feet and with the duration of findings. Lichen planus and atopic dermatitis morphology are inconsistent with this eruption, and coxsackie viral infection would have a shorter course.

Dr. Tracy is a research fellow in pediatric dermatology at Rady Children’s Hospital–San Diego and the University of California, San Diego. Dr. Eichenfield is chief of pediatric and adolescent dermatology at Rady Children’s Hospital–San Diego. He is vice chair of the department of dermatology and professor of dermatology and pediatrics at the University of California, San Diego. Email them at [email protected].

References

1. J Am Acad Dermatol. 2017 Feb;76(2):334-41.

2. Pediatr Dermatol. 2017 May;34(3):253-60.

3. RMD Open. 2016 Jul 15;2(2):e000239.

4. J Psoriasis Psoriatic Arthritis. 2019 Apr;4(2):70-80.

Tumor necrosis factor–alpha (TNF-alpha) inhibitors are therapeutic agents used to treat a variety of inflammatory conditions such as rheumatoid arthritis and inflammatory bowel disease, as well as psoriasis of the skin (PSO) and psoriatic arthritis. Paradoxically, some individuals report new onset of psoriasiform lesions with treatment with TNF-alpha inhibitors for other conditions. In a 2017 systematic review, there were 216 reported cases of new-onset TNF-alpha inhibitor–induced psoriasis, with an estimated rate of 1 per 1,000. The cases thus far have had a wide range of presentations, the most common being plaque psoriasis, scalp psoriasis, as well as palmoplantar pustular psoriasis.¹

Courtesy Dr. Lawrence F. Eichenfield

A retrospective chart review study at Mayo clinic published in 2017 evaluated children younger than 19 years seen in 2003-2015 who developed new-onset or recurrent PSO with a history of inflammatory bowel disease being treated with anti-TNF-alpha therapy. The review showed variable latency in the development of PSO in these patients, although it typically occurred during inflammatory bowel disease remission.² It is unclear whether there is an association between a personal or family history of psoriasis and development of these lesions.

TNF-alpha, interleukin (IL)–17) and interferon-alpha (IFN-alpha) are main cytokines that contribute to the development of psoriasis. The mechanism of action for paradoxical PSO/psoriasis in patients treated with anti-TNF is not clearly understood; however, many hypotheses are based on an imbalance between TNF-alpha and interferon-alpha – more specifically, an increased production of interferon-alpha. TNF-alpha inhibits the activity of plasmacytoid dendritic cells which are key producers of IFN-alpha. Because of this blockade, there is unopposed IFN-alpha production. Interferon-alpha allows for the expression of chemokines such as CXCR3, which favor T cells homing to the skin. IFN-alpha also stimulates and activates T cells to produce TNF-alpha and IL-17, which in turn sustains inflammatory mechanisms and allows for the development of psoriatic lesions.3

Courtesy Dr. Lawrence F. Eichenfield

There are no universal management guidelines. Most of these patients’ treatment plans mirror standard psoriasis therapies while the main question remains the decision to continue the same anti-TNF therapy, change anti-TNF agents, or entirely switch classes of biologic or other systemic therapy. This decision in management requires several considerations: treatability of TNF-alpha inhibitor-induced psoriasis, the severity of background disease (i.e., rheumatoid arthritis, inflammatory bowel disease, other systemic condition), and whether the underlying disease is well controlled on current therapy, as well as the consideration of possible loss in efficacy if a drug is discontinued and then restarted at a later date.⁴

A reasonable initial approach in patients with well-controlled underlying disease and mild skin eruption is to continue anti-TNF therapy and manage skin topically with topical corticosteroids and/or phototherapy. In patients that either do not have well-controlled underlying disease or moderate skin involvement, changing to an alternative anti-TNF or other agent may be reasonable, and requires coordinated care with involved specialists. In the 2017 pediatric review mentioned previously, nearly half of the patients required a change in their initial anti-TNF-alpha agent despite conventional skin-directed therapies, and one-third of patients discontinued all anti-TNF-alpha therapy because of PSO.²

The psoriasiform papulosquamous features of this case along with the history suggests the diagnosis. Pityriasis rosea would be highly atypical on the feet and with the duration of findings. Lichen planus and atopic dermatitis morphology are inconsistent with this eruption, and coxsackie viral infection would have a shorter course.

Dr. Tracy is a research fellow in pediatric dermatology at Rady Children’s Hospital–San Diego and the University of California, San Diego. Dr. Eichenfield is chief of pediatric and adolescent dermatology at Rady Children’s Hospital–San Diego. He is vice chair of the department of dermatology and professor of dermatology and pediatrics at the University of California, San Diego. Email them at [email protected].

References

1. J Am Acad Dermatol. 2017 Feb;76(2):334-41.

2. Pediatr Dermatol. 2017 May;34(3):253-60.

3. RMD Open. 2016 Jul 15;2(2):e000239.

4. J Psoriasis Psoriatic Arthritis. 2019 Apr;4(2):70-80.

Nummular dermatitis, or nummular eczema, is an inflammatory skin condition that is considered to be a distinctive form of idiopathic eczema, while the term also is used to describe lesional morphology associated with other conditions.

The term nummular derives from the Latin word for “coin,” as lesions are commonly annular plaques. Lesions of nummular dermatitis can be single or multiple. The typical distribution involves the extremities and, although less common, it can affect the trunk as well. The morphology of lesions is consistent with a localized eczematous reaction, with induration, oozing, crusting, and/or scaling.

Nummular dermatitis may be associated with atopic dermatitis, or it can be an isolated condition.¹ While the pathogenesis is uncertain, instigating factors include xerotic skin, insect bites, or scratches or scrapes.¹Staphylococcus infection or colonization, contact allergies to metals such as nickel and less commonly mercury, sensitivity to formaldehyde or medicines such as neomycin, and sensitization to an environmental aeroallergen (such as Candida albicans, dust mites) are considered risk factors.²

The diagnosis of nummular dermatitis is clinical. Laboratory testing and/or biopsy generally are not necessary, although a bacterial culture can be considered in patients with exudative and/or crusted lesions to rule out impetigo as a primary process of secondary infection. In some cases, patch testing for allergic contact dermatitis may be useful.

The differential diagnosis of nummular dermatitis includes tinea corporis (ringworm), atopic dermatitis, allergic contact dermatitis, impetigo, and psoriasis. Tinea corporis usually presents as annular lesions with a distinct peripheral scaling, rather than the diffuse induration of nummular dermatitis. Potassium hydroxide preparation or fungal culture can identify tinea species. Nummular dermatitis may be seen in patients with atopic dermatitis, who should have typical history, morphology, and course consistent with standard diagnostic criteria. Allergic contact dermatitis can present with regional, localized eczematous plaques in areas exposed to contact allergens. Patterns of lesions in areas of contact and worsening with repeat exposures can be clues to this diagnosis. Impetigo can present with honey-colored crusted lesions and/or superficial erosions, or purulent pyoderma. Lesions can be single or multiple and generally appear less inflammatory than nummular dermatitis. Psoriasis lesions may be annular, are more common on extensor surfaces, and usually have more prominent overlying pinkish, silvery white or micaceous scale.

Management of nummular dermatitis requires strong anti-inflammatory medications, usually mid-potency or higher topical corticosteroids, along with moisturizers and limiting exposure to skin irritants. “Wet wraps,” with application of topical corticosteroids to wet skin with occlusive wet dressings can enhance response. Transition from higher strength topical corticosteroids to lower strength agents used intermittently can help achieve remission or cure. Management practices include less frequent bathing with lukewarm water, using hypoallergenic cleansers and detergents, and applying moisturizers frequently. If plaques do recur, they tend to do so in the same location and in some patients resolution may result in hyper or hypopigmentation. Refractory disease may be managed with intralesional steroid injections, or systemic medications such as methotrexate.³

Dr. Tracy is a research fellow in pediatric dermatology at Rady Children’s Hospital–San Diego and the University of California, San Diego. Dr. Eichenfield is chief of pediatric and adolescent dermatology at Rady Children’s Hospital–San Diego. He is vice chair of the department of dermatology and professor of dermatology and pediatrics at the University of California, San Diego. Neither Dr. Tracy nor Dr. Eichenfield have any relevant financial disclosures. Email them at [email protected].

References

1. Pediatr Dermatol. 2012 Sep-Oct;29(5):580-3.

2. American Academy of Dermatology. Nummular Dermatitis Overview

3. Pediatr Dermatol. 2018 Sep;35(5):611-5.

Nummular dermatitis, or nummular eczema, is an inflammatory skin condition that is considered to be a distinctive form of idiopathic eczema, while the term also is used to describe lesional morphology associated with other conditions.

The term nummular derives from the Latin word for “coin,” as lesions are commonly annular plaques. Lesions of nummular dermatitis can be single or multiple. The typical distribution involves the extremities and, although less common, it can affect the trunk as well. The morphology of lesions is consistent with a localized eczematous reaction, with induration, oozing, crusting, and/or scaling.

Nummular dermatitis may be associated with atopic dermatitis, or it can be an isolated condition.¹ While the pathogenesis is uncertain, instigating factors include xerotic skin, insect bites, or scratches or scrapes.¹Staphylococcus infection or colonization, contact allergies to metals such as nickel and less commonly mercury, sensitivity to formaldehyde or medicines such as neomycin, and sensitization to an environmental aeroallergen (such as Candida albicans, dust mites) are considered risk factors.²

The diagnosis of nummular dermatitis is clinical. Laboratory testing and/or biopsy generally are not necessary, although a bacterial culture can be considered in patients with exudative and/or crusted lesions to rule out impetigo as a primary process of secondary infection. In some cases, patch testing for allergic contact dermatitis may be useful.

The differential diagnosis of nummular dermatitis includes tinea corporis (ringworm), atopic dermatitis, allergic contact dermatitis, impetigo, and psoriasis. Tinea corporis usually presents as annular lesions with a distinct peripheral scaling, rather than the diffuse induration of nummular dermatitis. Potassium hydroxide preparation or fungal culture can identify tinea species. Nummular dermatitis may be seen in patients with atopic dermatitis, who should have typical history, morphology, and course consistent with standard diagnostic criteria. Allergic contact dermatitis can present with regional, localized eczematous plaques in areas exposed to contact allergens. Patterns of lesions in areas of contact and worsening with repeat exposures can be clues to this diagnosis. Impetigo can present with honey-colored crusted lesions and/or superficial erosions, or purulent pyoderma. Lesions can be single or multiple and generally appear less inflammatory than nummular dermatitis. Psoriasis lesions may be annular, are more common on extensor surfaces, and usually have more prominent overlying pinkish, silvery white or micaceous scale.

Management of nummular dermatitis requires strong anti-inflammatory medications, usually mid-potency or higher topical corticosteroids, along with moisturizers and limiting exposure to skin irritants. “Wet wraps,” with application of topical corticosteroids to wet skin with occlusive wet dressings can enhance response. Transition from higher strength topical corticosteroids to lower strength agents used intermittently can help achieve remission or cure. Management practices include less frequent bathing with lukewarm water, using hypoallergenic cleansers and detergents, and applying moisturizers frequently. If plaques do recur, they tend to do so in the same location and in some patients resolution may result in hyper or hypopigmentation. Refractory disease may be managed with intralesional steroid injections, or systemic medications such as methotrexate.³

Dr. Tracy is a research fellow in pediatric dermatology at Rady Children’s Hospital–San Diego and the University of California, San Diego. Dr. Eichenfield is chief of pediatric and adolescent dermatology at Rady Children’s Hospital–San Diego. He is vice chair of the department of dermatology and professor of dermatology and pediatrics at the University of California, San Diego. Neither Dr. Tracy nor Dr. Eichenfield have any relevant financial disclosures. Email them at [email protected].

References

1. Pediatr Dermatol. 2012 Sep-Oct;29(5):580-3.

2. American Academy of Dermatology. Nummular Dermatitis Overview

3. Pediatr Dermatol. 2018 Sep;35(5):611-5.

Nummular dermatitis, or nummular eczema, is an inflammatory skin condition that is considered to be a distinctive form of idiopathic eczema, while the term also is used to describe lesional morphology associated with other conditions.

The term nummular derives from the Latin word for “coin,” as lesions are commonly annular plaques. Lesions of nummular dermatitis can be single or multiple. The typical distribution involves the extremities and, although less common, it can affect the trunk as well. The morphology of lesions is consistent with a localized eczematous reaction, with induration, oozing, crusting, and/or scaling.

Nummular dermatitis may be associated with atopic dermatitis, or it can be an isolated condition.¹ While the pathogenesis is uncertain, instigating factors include xerotic skin, insect bites, or scratches or scrapes.¹Staphylococcus infection or colonization, contact allergies to metals such as nickel and less commonly mercury, sensitivity to formaldehyde or medicines such as neomycin, and sensitization to an environmental aeroallergen (such as Candida albicans, dust mites) are considered risk factors.²

The diagnosis of nummular dermatitis is clinical. Laboratory testing and/or biopsy generally are not necessary, although a bacterial culture can be considered in patients with exudative and/or crusted lesions to rule out impetigo as a primary process of secondary infection. In some cases, patch testing for allergic contact dermatitis may be useful.

The differential diagnosis of nummular dermatitis includes tinea corporis (ringworm), atopic dermatitis, allergic contact dermatitis, impetigo, and psoriasis. Tinea corporis usually presents as annular lesions with a distinct peripheral scaling, rather than the diffuse induration of nummular dermatitis. Potassium hydroxide preparation or fungal culture can identify tinea species. Nummular dermatitis may be seen in patients with atopic dermatitis, who should have typical history, morphology, and course consistent with standard diagnostic criteria. Allergic contact dermatitis can present with regional, localized eczematous plaques in areas exposed to contact allergens. Patterns of lesions in areas of contact and worsening with repeat exposures can be clues to this diagnosis. Impetigo can present with honey-colored crusted lesions and/or superficial erosions, or purulent pyoderma. Lesions can be single or multiple and generally appear less inflammatory than nummular dermatitis. Psoriasis lesions may be annular, are more common on extensor surfaces, and usually have more prominent overlying pinkish, silvery white or micaceous scale.

Management of nummular dermatitis requires strong anti-inflammatory medications, usually mid-potency or higher topical corticosteroids, along with moisturizers and limiting exposure to skin irritants. “Wet wraps,” with application of topical corticosteroids to wet skin with occlusive wet dressings can enhance response. Transition from higher strength topical corticosteroids to lower strength agents used intermittently can help achieve remission or cure. Management practices include less frequent bathing with lukewarm water, using hypoallergenic cleansers and detergents, and applying moisturizers frequently. If plaques do recur, they tend to do so in the same location and in some patients resolution may result in hyper or hypopigmentation. Refractory disease may be managed with intralesional steroid injections, or systemic medications such as methotrexate.³

Dr. Tracy is a research fellow in pediatric dermatology at Rady Children’s Hospital–San Diego and the University of California, San Diego. Dr. Eichenfield is chief of pediatric and adolescent dermatology at Rady Children’s Hospital–San Diego. He is vice chair of the department of dermatology and professor of dermatology and pediatrics at the University of California, San Diego. Neither Dr. Tracy nor Dr. Eichenfield have any relevant financial disclosures. Email them at [email protected].

References

1. Pediatr Dermatol. 2012 Sep-Oct;29(5):580-3.

2. American Academy of Dermatology. Nummular Dermatitis Overview

3. Pediatr Dermatol. 2018 Sep;35(5):611-5.