Atopic dermatitis in African American children: addressing unmet needs of a common disease

Blocking the IL-4/IL-13 Axis versus the JAK/STAT Pathway in Atopic Dermatitis: How Can We Choose?

Atopic dermatitis (AD) is an immune-mediated skin disorder with a chronic-relapsing course and a multifactorial pathogenesis. In contrast to the traditional concept of AD as solely a type 2 immune-activated disease, new findings highlight the disease as highly heterogeneous, as it can be classified into variable phenotypes based on clinical/epidemiological or molecular parameters. For many years, the only therapeutic option for moderate-severe AD was traditional immunosuppressive drugs. Recently, the area of systemic therapy of AD has significantly flourished, and many new substances are now marketed, licensed, or in the last step of clinical development. Biological agents and small molecules have enriched the therapeutic armamentarium of moderate-to-severe AD, such as dupilumab, tralokinumab, lebrikizumab (monoclonal antibodies targeting the IL-4/13 pathway), abrocitinib, upadacitinib, and baricitinib (JAK inhibitors). Indeed, the AD treatment paradigm is now split into two main approaches: targeting the IL-4/13 axis or the JAK/STAT pathway. Both approaches are valid and have strong evidence of preclinical and clinical efficacy. Therefore, the choice between the two can often be difficult and represents a major challenge for dermatologists. Indeed, several important factors must be taken into account, such as the heterogeneity of AD and its classification in phenotypes, patients' comorbidities, age, and personal preferences. The aim of our review is to provide an overview of the clinical and molecular heterogeneities of AD and to explore the factors and parameters that, in clinical practice, may help inform clinical decision-making.

[Inflammatory dermatoses in children and adolescents : Diagnosis and treatment of atopic dermatitis and psoriasis]

Atopic dermatitis (AD) and psoriasis belong to the most common inflammatory dermatoses that we treat in everyday clinical practice. AD manifests in more than 70% of cases before the age of 5 years. Approximately one-third of psoriasis patients report on onset of disease in the first two decades of life. Here, we are going to review both disorders in the light of pediatric dermatology. We are going to discuss selected subtypes and present clues for further examination with respect to the differential diagnoses and comorbidities. The article provides insight into current therapeutic developments that are relevant for the treatment of children and adolescents.

Abrocitinib efficacy and safety in moderate-to-severe atopic dermatitis by race, ethnicity, and Fitzpatrick skin type

BACKGROUND

Response to abrocitinib treatment for moderate-to-severe atopic dermatitis (AD) has not been evaluated across racial and ethnic subpopulations.

OBJECTIVE

To assess the efficacy and safety of abrocitinib on the basis of patient race, ethnicity, and Fitzpatrick skin type (FST).

METHODS

Data were pooled post hoc from patients treated with abrocitinib 200 mg, 100 mg, or placebo in 3 monotherapy trials (NCT02780167, NCT03349060, and NCT03575871). Race and ethnicity were self-reported; FST was determined by study investigators. Evaluations through Week 12 include the following: (1) Investigator's Global Assessment of clear or almost-clear skin; (2) greater than or equal to 75% improvement in Eczema Area and Severity Index or SCORing AD; (3) a greater-than-or-equal-to 4-point improvement in Peak Pruritus Numerical Rating Scale score; (4) least squares mean changes in Dermatology Life Quality Index and Patient-Oriented Eczema Measure scores; and (5) treatment-emergent adverse events.

RESULTS

The sample comprised 628 White, 204 Asian, and 83 Black patients; 37 were Hispanic or Latino; 624 had FST I to III and 320 had FST IV to VI. Treatment with either abrocitinib dose was associated with greater proportions of patients achieving Investigator's Global Assessment of clear or almost-clear skin, ≥ 75% improvement in Eczema Area and Severity Index, ≥ 75% improvement in SCORing AD, and a ≥ 4-point improvement in Peak Pruritus Numerical Rating Scale, or greater score changes from baseline in Dermatology Life Quality Index and Patient-Oriented Eczema Measure vs placebo regardless of race, ethnicity, or FST. Dose-response was most prominent in White patients. In Black patients, the effects of the 2 doses were similar. Treatment-emergent adverse events were more common in White and Black than in Asian patients.

CONCLUSION

Abrocitinib was more efficacious than placebo across the racial and ethnic groups and ranges of phototypes analyzed. Studies with increased representation of populations of color are warranted to elucidate potential variations in response across diverse populations.

TRIAL REGISTRATION

Clinicaltrials.gov Identifier: NCT02780167 (phase 2b), NCT03349060 (phase 3 MONO-1), and NCT03575871 (phase 3 MONO-2).

Atopic dermatitis (eczema) guidelines: 2023 American Academy of Allergy, Asthma and Immunology/American College of Allergy, Asthma and Immunology Joint Task Force on Practice Parameters GRADE- and Institute of Medicine-based recommendations

BACKGROUND

Guidance addressing atopic dermatitis (AD) management, last issued in 2012 by the American Academy of Allergy, Asthma and Immunology/American College of Allergy, Asthma and Immunology Joint Task Force, requires updating as a result of new treatments and improved guideline and evidence synthesis methodology.

OBJECTIVE

To produce evidence-based guidelines that support patients, clinicians, and other decision-makers in the optimal treatment of AD.

METHODS

A multidisciplinary guideline panel consisting of patients and caregivers, AD experts (dermatology and allergy/immunology), primary care practitioners (family medicine, pediatrics, internal medicine), and allied health professionals (psychology, pharmacy, nursing) convened, prioritized equity, diversity, and inclusiveness, and implemented management strategies to minimize influence of conflicts of interest. The Evidence in Allergy Group supported guideline development by performing systematic evidence reviews, facilitating guideline processes, and holding focus groups with patient and family partners. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach informed rating the certainty of evidence and strength of recommendations. Evidence-to-decision frameworks, subjected to public comment, translated evidence to recommendations using trustworthy guideline principles.

RESULTS

The panel agreed on 25 recommendations to gain and maintain control of AD for patients with mild, moderate, and severe AD. The eAppendix provides practical information and implementation considerations in 1-2 page patient-friendly handouts.

CONCLUSION

These evidence-based recommendations address optimal use of (1) topical treatments (barrier moisturization devices, corticosteroids, calcineurin inhibitors, PDE4 inhibitors [crisaborole], topical JAK inhibitors, occlusive [wet wrap] therapy, adjunctive antimicrobials, application frequency, maintenance therapy), (2) dilute bleach baths, (3) dietary avoidance/elimination, (4) allergen immunotherapy, and (5) systemic treatments (biologics/monoclonal antibodies, small molecule immunosuppressants [cyclosporine, methotrexate, azathioprine, mycophenolate, JAK inhibitors], and systemic corticosteroids) and UV phototherapy (light therapy).

Development of an Eczema Area and Severity Index Atlas for Diverse Skin Types

Background: Current guidance for using Eczema Area and Severity Index (EASI) implementation is limited to lighter skin phototypes. We developed an EASI lesion severity atlas and refined guidance for investigators and clinicians to use across diverse patient populations. Methods: A review was performed of clinical images from internal atopic dermatitis (AD) photorepositories. Representative images of the 4 AD signs included in EASI were selected for different physician-assessed skin phototypes. Images were excluded if they had low resolution, poor focus, or lighting. Discrepancies regarding skin pigmentation and AD severity were resolved by consensus between authors. Results: Over 3000 clinical photographs were reviewed. Final images were selected using an iterative review process and consensus. Two different versions of the atlas were created across 6 physician-assessed phototypes (I-VI) and 3 skin complexions (light, medium, and dark). We propose guidance language for erythema to reflect the range of colors encountered across different skin complexions (shades of red, purple, and brown). Conclusion: We created a photographic atlas and updated guidance language for implementing EASI in diverse populations, including those with higher skin phototypes.

Phenotypes, endotypes and genotypes of atopic dermatitis and allergy in populations of African ancestry on the continent and diaspora

Atopic dermatitis is a complex inflammatory condition characterized by synergist interactions between epidermal and immune related genotypes, skin barrier defects and immune dysregulation as well as microbial dysbiosis. Ethnicity-specific variations in clinical presentation, immune endotypes and genetic susceptibility have been described in diverse populations. We summarize available data with specific consideration of AD in populations of African ancestry. Some highlights include the observation of AD lesions on extensor surfaces, lichen planus-like AD, prurigo type AD and follicular AD in African populations. In addition, a consistent absence of dominant filaggrin gene defects has been reported. The detection of normal filaggrin protein content in AD skin implicates the contribution of alternative mechanisms in the pathogenesis of AD in African patients. Markedly high IgE has been described in paediatric and adult African AD. While Th2, Th22 and Th17 activation in African AD skin shares the same direction as with other populations, it has been noted that the magnitude of activation is dissimilar. Reduced Th17 cytokines have been observed in the circulation of moderate to severe paediatric AD.

Atopic Dermatitis in Individuals of Asian and African Ancestry: A Scoping Systematic Review

INTRODUCTION

Atopic Dermatitis (AD) affects individuals from all ethnicities and backgrounds. It has the highest global disease burden of dermatoses. There is a widely held belief that the presentation of AD is not described well in individuals with non-European ancestry in peer-reviewed literature. However, to our knowledge, this has not been investigated previously.

OBJECTIVE

To quantify the number of peer-reviewed literature describing the appearance of clinical features of AD in non-European ancestry, particularly those originating from the Asian and African continents.

METHODS

A systematic scoping review between December 2020 and January 2021 was performed to quantify the number of studies describing AD in individuals of African and Asian ancestry.

RESULTS

Sixteen studies were identified. None of the studies provided a clear description of AD in our population groups. Two studies described features of lichen planus like-AD in African American individuals. All studies reported on observed clinical features of AD.

CONCLUSIONS

The review confirmed a lack of literature describing AD in populations of non-European heritage. It should encourage authors to make a deliberate effort to describe the appearance of clinical features of AD to enable understanding of how they may differentiate in individuals originating from different parts of the globe.

Atopic dermatitis in skin of colour. Part 2: considerations in clinical presentation and treatment options

Recent advances in atopic dermatitis (AD) present the condition as a heterogeneous disease of distinct endotypes across ethnic groups. AD in people with skin of colour may appear psoriasiform, lichenoid, scaly or papular, with a violaceous colour and there is a higher prevalence of post-inflammatory dyspigmentation compared with affected individuals of White ethnicity. These differences in clinical presentation may limit the use of AD assessment tools in people with skin of colour, leading to the potential for misdiagnosis and underestimation of severity, particularly in relation to assessment of erythema. Recent targeted therapies for AD have been studied in multiple ethnic groups; however, ethnicity-based subgroup analysis is often not performed. Further research is required to understand whether treatment responses or safety may differ among ethnic groups.

Atopic Dermatitis Across Shades of Skin

Atopic dermatitis (AD) is a chronic, heterogeneous inflammatory skin disease that is associated with immense patient burden globally. There is increasing appreciation of disparities among patients identified as having skin of color (SOC), which often refers to patients of non-White race or non-European ancestry, but can broadly include individuals from a number of different racial, ethnic, ancestral, and skin pigmentation groups based on definition. In this narrative review, we discuss key terminology as it relates to AD across shades of skin, including modern definitions of 'race', 'ethnicity', and 'SOC'. We then synthesize the current literature describing disparities in AD prevalence, disease recognition, and burden alongside current data regarding genetic and immunologic findings across SOC populations. In the context of these findings, we highlight key concomitant social determinants of health, including environmental factors, socioeconomic status, and access to care, for which race often serves as a proxy for true biological and genetic differences. Finally, we discuss future efforts to shift to a more inclusive understanding of AD to encompass all shades of skin, to ensure equitable representation of diverse populations in high impact research, and intensify efforts to address the critical upstream factors driving observed disparities.

Racial and Ethnic Differences in Sociodemographic, Clinical, and Treatment Characteristics Among Patients with Atopic Dermatitis in the United States and Canada: Real-World Data from the CorEvitas Atopic Dermatitis Registry

INTRODUCTION

This real-world, cross-sectional study compared sociodemographic, clinical and treatment characteristics, and patient-reported outcomes (PROs) among racial/ethnic groups in patients with atopic dermatitis (AD) who are candidates for systemic therapy.

METHODS

This study included adults with dermatologist- or dermatology practitioner-diagnosed AD enrolled in the CorEvitas AD Registry (July 2020-July 2021). All patients initiated systemic therapy within 12 months prior to or at enrollment or had moderate-to-severe AD (vIGA-AD® ≥ 3 and Eczema Area and Severity Index [EASI] ≥ 12) at enrollment. Patients were categorized into five mutually exclusive racial/ethnic groups: non-Hispanic White, Black, Asian, Other/Multiracial, and Hispanic (any race). Patient, clinical, and treatment characteristics were captured at enrollment. Differences in means or proportions of characteristics among racial/ethnic groups were descriptively summarized using effect sizes. Adjusted prevalence ratios and mean differences were estimated (White race/ethnicity group as the reference category) with 95% confidence intervals (CI).

RESULTS

Among 1288 patients, 64% (n = 822) were White, 13% (n = 167) Black, 10% (n = 129) Asian, 8% (n = 97) Hispanic, and 6% (n = 73) Other/Multiracial. In adjusted analyses, statistically more severe EASI lichenification was noted among Black compared with White patients at the head and neck (mean difference, 0.21, [95% CI 0.06, 0.36]; p = 0.01), trunk (0.32, [0.17, 0.47]; p < 0.001), upper extremities (0.27, [0.09, 0.44]; p = 0.008), and lower extremities (0.39, [0.21, 0.57]; p < 0.001). Statistically more severe EASI lichenification was observed among Asian vs White patients in certain areas (mean difference, head and neck, 0.22 [0.04, 0.39], p = 0.01; trunk, 0.25 [0.07, 0.43], p < 0.001; lower extremities, 0.22 [0.01, 0.43], p < 0.001) and SCORing for AD lichenification (mean difference: 0.34 [0.15, 0.52]; p < 0.001). Significantly higher mean pruritus over the past 7 days for Black (mean difference: 0.63 [0.01, 1.26] and Hispanic patients (0.60 [0.11, 1.09]; p = 0.03) vs White patients was observed. Among AD clinical features, the prevalence of facial erythema was significantly lower among Black compared with White patients (prevalence ratio = 0.38, [0.22, 0.67]; p = 0.007).

CONCLUSION

Racial/ethnic differences exist in sociodemographic, clinical and treatment characteristics, disease severity, and PROs among real-world AD patients who are candidates for systemic therapy. Recognizing these variations may be of critical importance for dermatologists for the design and delivery of targeted/personalized medicine approaches.

Disorders in Children

Pediatric dermatoses can present at birth or develop over time. When managing dermatology conditions in children, caregiver involvement is important. Patients may have lesions that need to be monitored or need assistance with therapeutic administration. The following section provides a subset of pediatric dermatoses and notable points for presentation in skin of color patients. Providers need to be able to recognize dermatology conditions in patients of varying skin tones and provide therapies that address the condition and any associated pigmentary alterations.

Diagnosing Atopic Dermatitis in Skin of Color

Atopic dermatitis (AD) is a pruritic inflammatory skin disease that disproportionately affects skin of color patients. African American, Asian, and Hispanic patients carry disproportionate disease burdens, with increased prevalence, disease severity, and health care utilization. AD has a unique clinical presentation in skin of color patients, often with greater extensor involvement, dyspigmentation, and papular and lichenified presentations. Erythema is also more difficult to appreciate and can result in an underappreciation of disease severity in skin of color patients. In this review, we highlight the important manifestations of AD across all skin types, including nuances in treatment.

Managing Atopic Dermatitis in Patients With Skin of Color

Managing atopic dermatitis (AD) in patients with skin of color presents unique challenges for the clinician. There is increasing evidence that AD has higher prevalence, persistence, and severity among skin of color populations. This is likely to be partly related to differences in living conditions and exposure to irritants and allergens, among other factors. Assessment of AD severity in patients with darker skin can be challenging, in particular the assessment of erythema, leading to the potential for underscoring AD severity. Variations in disease have also been described, with the potential for a greater risk of inflammation-induced nodularity and hyper- or hypopigmentation. Management challenges include variable adherence to treatment, potential disparities in access to health care, and differences in the metabolism of cyclosporine. Optimal management of AD in patients with skin of color requires a tailored approach. Here, we review approaches to diagnosing AD, evaluating extent and severity with subjective and objective measures, considering treatment options for patients with skin of color, and highlighting areas for improvement in AD care for skin of color populations.

Overview of Atopic Dermatitis in Different Ethnic Groups

Atopic dermatitis (AD) is a common chronic inflammatory skin disease with a high prevalence worldwide, including countries from Asia, Africa, and Latin America, and in different ethnic groups. In recent years, more attention has been placed on the heterogeneity of AD associated with multiple factors, including a patient's ethnic background, resulting in an increasing body of clinical, genetic, epidemiologic, and immune-phenotypic evidence that delineates differences in AD among racial groups. Filaggrin (FLG) mutations, the strongest genetic risk factor for the development of AD, are detected in up to 50% of European and 27% of Asian AD patients, but very rarely in Africans. Th2 hyperactivation is a common attribute of all ethnic groups, though the Asian endotype of AD is also characterized by an increased Th17-mediated signal, whereas African Americans show a strong Th2/Th22 signature and an absence of Th1/Th17 skewing. In addition, the ethnic heterogeneity of AD may hold important therapeutic implications as a patient's genetic predisposition may affect treatment response and, thereby, a tailored strategy that better targets the dominant immunologic pathways in each ethnic subgroup may be envisaged. Nevertheless, white patients with AD represent the largest ethnicity enrolled and tested in clinical trials and the most treated in a real-world setting, limiting investigations about safety and efficacy across different ethnicities. The purpose of this review is to describe the heterogeneity in the pathophysiology of AD across ethnicities and its potential therapeutic implications.

Atopic Dermatitis: Diagnosis, Disparity, and Management in Children of Color

Atopic dermatitis (AD), sometimes referred to as eczema, is the most common chronic skin condition in children. Children of color have a higher reported prevalence of AD compared with their White counterparts. The purpose of this article is to discuss the differences of AD in skin of color (SOC), including clinical findings and management, with an emphasis on early recognition to avoid more severe, persistent disease. School nurses are on the frontline for these students with their ability to guide families and help support students with AD in the school setting.

Disparities in Cutaneous T-Cell Lymphoma Incidence by Race/Ethnicity and Area-Based Socioeconomic Status

Cutaneous T-cell lymphoma (CTCL) is a rare type of extranodal non-Hodgkin lymphoma (NHL). This study uses population-based data from the New Jersey (NJ) State Cancer Registry to examine geographic variation in CTCL incidence and evaluates whether CTCL risk varies by race/ethnicity and census tract socioeconomic status (SES). The study included 1163 cases diagnosed in NJ between 2006 and 2014. Geographic variation and possible clustering of high CTCL rates were assessed using Bayesian geo-additive models. The associations between CTCL risk and race/ethnicity and census tract SES, measured as median household income, were examined using Poisson regression. CTCL incidence varied across NJ, but there were no statistically significant geographic clusters. After adjustment for age, sex, and race/ethnicity, the relative risk (RR) of CTCL was significantly higher (RR = 1.47, 95% confidence interval: 1.22-1.78) in the highest income quartile than in the lowest. The interactions between race/ethnicity and SES indicated that the income gradients by RR were evident in all groups. Compared to non-Hispanic White individuals in low-income tracts, CTCL risk was higher among non-Hispanic White individuals in high-income tracts and among non-Hispanic Black individuals in tracts of all income levels. Our findings suggest racial disparities and a strong socioeconomic gradient with higher CTCL risk among cases living in census tracts with higher income compared to those living in lower-income tracts.

[Inflammatory dermatoses in skin of color]

Acne, rosacea, atopic dermatitis, and psoriasis vulgaris are common inflammatory dermatoses. Of note, the epidemiology and clinical presentation of these common dermatologic diseases varies considerably between people with different colors of skin. Yet, most dermatology textbooks present and describe the clinical pictures of White people. To provide excellent dermatological care for all patients, it is of central importance to know the epidemiology and recognize key clinical characteristics of these diseases in patients with skin of color (SOC). In acne, cultural habits of Blacks (use of steroid-based lighteners, comedogenic hair care products) may lead to manifestation of specific forms of acne. In addition, postinflammatory hyperpigmentation and keloids pose particular therapeutic challenges in this patient group. Atopic dermatitis in Asians shows a clinical and histological picture that is similar to psoriasis in Whites. By contrast, atopic dermatitis manifests on the extensor side in Black people. Due to the difficulty of recognizing erythema in SOC, the severity of the respective inflammatory diseases in these individuals is often underestimated. The treatment of acne, rosacea, atopic dermatitis, and psoriasis does not differ between people of different skin colors. The exception is the necessary therapy for postinflammatory hyperpigmentation in all the inflammatory dermatoses mentioned, and for keloids in acne.

Racial disparities in dermatology

Significant racial/ethnic disparities in dermatologic care and their subsequent impact on dermatologic conditions were recently reported. Contributing factors include socioeconomic factors, gaps in educational exposure, and underrepresentation of minority groups in the dermatologic workforce. In 2021, the American Academy of Dermatology (AAD) announced its three-year plan to expand diversity, equity, and inclusion in dermatology. One way to reduce disparities in dermatology is for every dermatologist, regardless of race or ethnicity, to receive adequate education in diseases, treatments, health equity, and tailored approaches to delivering dermatologic care with cultural humility. In addition, a diverse dermatologic workforce-especially at the level of residency program educators and organizational leaders-will contribute to improved cross-cultural understanding, more inclusive research efforts, and improved treatment approaches for conditions that are more prevalent or nuanced in certain racial/ethnic populations. Finally, the dermatology and broader healthcare community needs to acknowledge and educate ourselves on the health impacts of racism.

Variations in genetics, biology, and phenotype of cutaneous disorders in skin of color. Part II: Differences in clinical presentation and disparities in cutaneous disorders in skin of color

Skin of color (SOC) patients are projected to comprise the majority of the population by 2044, yet knowledge gaps in the clinical presentation and treatment of both common and uncommon dermatologic conditions in skin of color persist. Improved awareness of disparities that disproportionately impact SOC patients is necessary to address health inequity in the field of dermatology. The first part of this CME discussed structural, genetic, and immunophenotypic differences in SOC in common inflammatory disorders as well as cutaneous malignancies. The second part of this CME highlights clinical differences in the phenotypic presentation of the inflammatory disorders of atopic dermatitis, psoriasis, and hidradenitis suppurativa as well as the cutaneous malignancies of melanoma, basal cell carcinoma, and cutaneous T-cell lymphoma. Health disparities associated with each of these conditions are also discussed.

PIEZO1 transduces mechanical itch in mice

Itch triggers scratching, a behavioural defence mechanism that aids in the removal of harmful irritants and parasites¹. Chemical itch is triggered by many endogenous and exogenous cues, such as pro-inflammatory histamine, which is released during an allergic reaction¹. Mechanical itch can be triggered by light sensations such as wool fibres or a crawling insect². In contrast to chemical itch pathways, which have been extensively studied, the mechanisms that underlie the transduction of mechanical itch are largely unknown. Here we show that the mechanically activated ion channel PIEZO1 (ref. ³) is selectively expressed by itch-specific sensory neurons and is required for their mechanically activated currents. Loss of PIEZO1 function in peripheral neurons greatly reduces mechanically evoked scratching behaviours and both acute and chronic itch-evoked sensitization. Finally, mice expressing a gain-of-function Piezo1 allele⁴ exhibit enhanced mechanical itch behaviours. Our studies reveal the polymodal nature of itch sensory neurons and identify a role for PIEZO1 in the sensation of itch.

Experiments in mice show that the mechanically activated ion channel PIEZO1 is expressed in itch-specific sensory neurons and has a role in transducing mechanical itch.

Burden of allergic disease among ethnic minority groups in high-income countries

The COVID‐19 pandemic raised acute awareness regarding inequities and inequalities and poor clinical outcomes amongst ethnic minority groups. Studies carried out in North America, the UK and Australia have shown a relatively high burden of asthma and allergies amongst ethnic minority groups. The precise reasons underpinning the high disease burden are not well understood, but it is likely that this involves complex gene–environment interaction, behavioural and cultural elements. Poor clinical outcomes have been related to multiple factors including access to health care, engagement with healthcare professionals and concordance with advice which are affected by deprivation, literacy, cultural norms and health beliefs. It is unclear at present if allergic conditions are intrinsically more severe amongst patients from ethnic minority groups. Most evidence shaping our understanding of disease pathogenesis and clinical management is biased towards data generated from white population resident in high‐income countries. In conjunction with standards of care, it is prudent that a multi‐pronged approach towards provision of composite, culturally tailored, supportive interventions targeting demographic variables at the individual level is needed, but this requires further research and validation. In this narrative review, we provide an overview of epidemiology, sensitization patterns, poor clinical outcomes and possible factors underpinning these observations and highlight priority areas for research.

Roles Played by Stress-Induced Pathways in Driving Ethnic Heterogeneity for Inflammatory Skin Diseases

Immune-mediated skin conditions (IMSCs) are a diverse group of autoimmune diseases associated with significant disease burden. Atopic dermatitis and psoriasis are among the most common IMSCs in the United States and have disproportionate impact on racial and ethnic minorities. African American patients are more likely to develop atopic dermatitis compared to their European American counterparts; and despite lower prevalence of psoriasis among this group, African American patients can suffer from more extensive disease involvement, significant post-inflammatory changes, and a decreased quality of life. While recent studies have been focused on understanding the heterogeneity underlying disease mechanisms and genetic factors at play, little emphasis has been put on the effect of psychosocial or psychological stress on immune pathways, and how these factors contribute to differences in clinical severity, prevalence, and treatment response across ethnic groups. In this review, we explore the heterogeneity of atopic dermatitis and psoriasis between African American and European American patients by summarizing epidemiological studies, addressing potential molecular and environmental factors, with a focus on the intersection between stress and inflammatory pathways.

Art of prevention: Atopic dermatitis in women and families of color-prevalence, recognition, and prevention

Atopic dermatitis (AD) is one of the most common skin conditions encountered by dermatologists. Skin of color (SOC) patients, in particular, are 50% more likely to visit a dermatologist for AD than non-SOC patients. While the misdiagnosis of AD in SOC patients is rare, the misinterpretation of severity or undertreatment of disease experienced by this patient population is a common occurrence. Herein, we present this Art of Prevention piece focused on the epidemiology, presentation, treatment, and management of AD in skin of color patients.

Dermatology for the internist: optimal diagnosis and management of atopic dermatitis

Internists are front-line health care providers that commonly provide the first encounter to patients for dermatological conditions, especially atopic dermatitis (AD). Internists need to be comfortable with managing mild-moderate AD in their practices. Criteria and guidelines established in dermatology literature are available to help the general practitioner diagnose and treat AD. AD is a systemic disease associated with multiple cutaneous and extra-cutaneous comorbidities that warrant screening by internists, especially mental health conditions. Environmental factors may play a role in the development or worsening of AD; however, there is currently no strong evidence to guide specific population- or clinic-based interventions for their avoidance. While food allergies are common in AD patients, the role of food allergens as an exacerbating factor for AD is controversial. Before starting any dietary modifications, careful evaluation should be performed by an allergist. If the patient is not well-controlled despite adequate topical therapies or is experiencing severe/worsening disease, early referral to dermatology is warranted to rule out confounding diagnoses and/or escalation to systemic therapies. Finally, it is important to recognise the racial disparities present in AD and address these when formulating treatment plans.Key messages:Confounding dermatoses, either instead of or in addition to AD, should be considered in treatment-refractory AD, and the appropriate workup may be initiated while awaiting dermatology referral.AD patients have multiple cutaneous and extra-cutaneous comorbidities that warrant screening by internists, especially mental health conditions.

Review article: Emerging issues in pediatric skin of color, Part 2

Dermatology for pediatric skin of color is the application of dermatology to the genetically diverse and distinctive segment of the pediatric population that includes children of non-White racial and ethnic groups with increased pigmentation including individuals of Asian, Hispanic/LatinX, African, Native American, Pacific Island descent, indigenous people among others with overlap in particular individuals, and mixtures thereof. The discipline of pediatric skin of color can be challenging with difficulty in diagnosis of common conditions due to underlying pigmentation, variations in common hair styling practices, and differences in demographics of cutaneous disease. Whereas some conditions are more common in children of color, other conditions have nuances in clinical appearance and therapeutics with regard to skin color. This article, the second of the series, focuses on inflammatory skin disease nuances, melanocytic disorders, and hypopigmented mycosis fungoides.

Reframing racial and ethnic disparities in atopic dermatitis in Black and Latinx populations

Black people in the United States experience greater atopic dermatitis (AD) prevalence, severity, and persistence when compared with White people. Although very little published literature describes AD in the Latinx population, additional differences in severity, persistence, and age of onset exist in contrast to White people. Thus far, genetic polymorphisms associated with increased risk and/or severity of AD are less common among Black people, so should confer reduced, rather than the observed increased, AD risk among Black people. Little is known regarding genetic risk factors in Latinx people. In contrast, there is consistent evidence that socioeconomic, environmental, and health care factors influence AD prevalence, severity, and/or persistence, and these same risk factors are more common among racial and ethnic minority populations as a result of racism. Researchers too often pursue genetic explanations for racial and ethnic AD disparities when the evidence points to the importance of contextual, rather than genetic, causes of these disparities. Reframing the prevailing view that innate differences among racial and ethnic groups are responsible for these disparities by emphasizing the role of racism and its downstream effects on contextual factors will be a critical first step toward shrinking these disparities.

Immune and barrier characterization of atopic dermatitis skin phenotype in Tanzanian patients

BACKGROUND

Atopic dermatitis (AD) is a common disease, with particularly high prevalence found in Africa. It is increasingly recognized that patients with AD of different ethnic backgrounds have unique molecular signatures in the skin, potentially accounting for treatment response variations. Nevertheless, the skin profile of patients with AD from Africa is unknown, hindering development of new treatments targeted to this patient population.

OBJECTIVE

To characterize the skin profile of patients with AD from Africa.

METHODS

Gene expression studies, including RNA sequencing (using threshold of fold change of >2 and false discovery rate of <0.05) and real-time polymerase chain reaction, were performed on skin biopsies of Tanzanian patients with moderate-to-severe AD and controls.

RESULTS

Tanzanian AD skin presented robust up-regulations of multiple key mediators of both T helper 2 (TH2) (interleukin 13 [IL-13], IL-10, IL-4R, CCL13,CCL17,CCL18,CCL26) and TH22 (IL22, S100As) pathways. Markers related to TH17 and IL-23 (IL-17A, IL-23A, IL-12, PI3, DEFB4B) and TH1 (interferon gamma, CXCL9,CXCL10,CXCL11) were also significantly overexpressed in AD tissues (FDR<.05), albeit to a lesser extent. IL-36 isoforms revealed substantial up-regulations in African skin. The barrier fingerprint of Tanzanian AD revealed no suppression of hallmark epidermal barrier differentiation genes, such as filaggrin, loricrin, and periplakin, with robust attenuation of lipid metabolism genes (ie, AWAT1).

CONCLUSION

The skin phenotype of Tanzanian patients with AD is consistent with that of African Americans, exhibiting dominant TH2 and TH22 skewing, minimal dysregulation of terminal differentiation, and even broader attenuation of lipid metabolism-related products. These data highlight the unique characteristic of AD in Black individuals and the need to develop unique treatments targeting patients with AD from these underrepresented populations.

Association between atopic dermatitis and race from infancy to early childhood: a retrospective cohort study

BACKGROUND

Atopic dermatitis (AD) is a common pediatric skin condition with significant morbidity. It is unclear what factors contribute to racial differences in disease prevalence.

METHODS

A single-site, retrospective cohort study of infants born from June 1, 2011, to April 30, 2017, was performed.

RESULTS

Of the 4016 infants included, 39.2% (n = 1574) were Black, 38.5% (n = 1543) White (non-Hispanic), 7.1% (n = 286) Hispanic, 5.3% (n = 213) Asian, 6.5% (n = 262) "other" race, 3.4% (n = 135) multiracial, and 0.1% (n = 3) not reported. Prevalence of AD differed by race, with 37.0% (n = 583) of Black, 25.8% (n = 55) of Asian, 24.1% (n = 69) of Hispanic, 23.0% (n = 31) of multiracial, 19.1% (n = 50) of "other" race, and 17.9% (n = 276) of White patients diagnosed (P < 0.0001). Delivery mode, NICU stay, and gestational age were all significantly associated with race. In modeling AD with logistic regression, race was significantly associated with the development of AD (P < 0.0001, OR Black = 2.6 [2.2-3.2], OR Asian = 1.6 [1.1-2.2], OR Hispanic = 1.4 [1.0-1.9], OR multiracial 1.4 [0.91-2.2], OR "other" 0.97 [0.67-1.4], and OR White 1.0).

CONCLUSIONS

Racial differences in rates of AD arise early in life. Diagnosis is associated with race rather than delivery mode, insurance type, and gestational age. Further investigation into these disparities and interventions to mitigate them should focus on infancy and early childhood.

Chronic itch in African Americans: an unmet need

Chronic pruritus carries a significant burden of disease and is associated with a negative impact on quality of life. African Americans are disproportionately burdened by chronic pruritic disorders, including but not limited to atopic dermatitis, prurigo nodularis, inflammatory scalp dermatoses, pathologic scarring, and HIV-related dermatoses. Racial differences in skin structure and function may contribute to the pathogenesis of itch in African Americans. Itch perception and response to treatment in African Americans remain understudied and not well understood. As such, there is a large unmet need with regard to the knowledge and management of pruritus in African Americans. This review highlights notable differences in the epidemiology, pathophysiology, genetic predisposition, clinical presentation, and response to treatment for select pruritic skin conditions. By addressing itch as an unmet need in African Americans, we hope to improve patient outcomes and lessen disparities in dermatologic care.

Transcriptomic analysis of atopic dermatitis in African Americans is characterized by Th2/Th17-centered cutaneous immune activation

Atopic dermatitis (AD) often presents more severely in African Americans (AAs) and with greater involvement of extensor areas. To investigate immune signatures of AD in AAs with moderate to severe pruritus, lesional and non-lesional punch biopsies were taken from AA patients along with age-, race-, and sex-matched controls. Histology of lesional skin showed psoriasiform dermatitis and spongiotic dermatitis, suggesting both Th2 and Th17 activity. Gene Set Variation Analysis showed upregulation of Th2 and Th17 pathways in both lesional versus non-lesional and lesional versus control (p < 0.01), while Th1 and Th22 upregulation were observed in lesional versus control (p < 0.05). Evidence for a broad immune signature also was supported by upregulated Th1 and Th22 pathways, and clinically may represent greater severity of AD in AA. Furthermore, population-level analysis of data from TriNetX, a global federated health research network, revealed that AA AD patients had higher values for CRP, ferritin, and blood eosinophils compared to age-, sex-, and race-matched controls as well as white AD patients, suggesting broad systemic inflammation. Therefore, AA AD patients may feature broader immune activation than previously thought and may derive benefit from systemic immunomodulating therapies that modulate key drivers of multiple immune pathways.

Nomenclature and clinical phenotypes of atopic dermatitis

Atopic dermatitis is a heterogeneous disease and resists classification. In this review, we discuss atopic dermatitis nomenclature and identify morphologic phenotypes, which will facilitate correct diagnoses and development of treatment strategies. We support using the term 'atopic dermatitis' rather than eczema, because it describes the allergic background and inflammation ('itis') as drivers of the disease. Atopic dermatitis has many morphologic manifestations that vary by topographic area affected, age, or race and require consideration in differential diagnosis. Different phenotypes based on morphology and topographic location, ethnicity, and age are discussed. A better-defined phenotype identification for atopic dermatitis will facilitate earlier and correct diagnosis of this complex condition and inform selection of the most appropriate treatment choice in an era in which targeted therapies may generate more individualized patient care.

Health disparities in allergic and immunologic conditions in racial and ethnic underserved populations: A Work Group Report of the AAAAI Committee on the Underserved

Health disparities are health differences linked with economic, social, and environmental disadvantage. They adversely affect groups that have systematically experienced greater social or economic obstacles to health. Renewed efforts are needed to reduced health disparities in the United States, highlighted by the disparate impact on racial minorities during the coronavirus pandemic. Institutional or systemic patterns of racism are promoted and legitimated through accepted societal standards, and organizational processes within the field of medicine, and contribute to health disparities. Herein, we review current evidence regarding health disparities in allergic rhinitis, asthma, atopic dermatitis, food allergy, drug allergy, and primary immune deficiency disease in racial and ethnic underserved populations. Best practices to address these disparities involve addressing social determinants of health and adopting policies to improve access to specialty care and treatment for the underserved through telemedicine and community partnerships, cross-cultural provider training to reduce implicit bias, inclusion of underserved patients in research, implementation of culturally competent patient education, and recruitment and training of health care providers from underserved communities. Addressing health disparities requires a multilevel approach involving patients, health providers, local agencies, professional societies, and national governmental agencies.

Sociocultural Influences on Disparities in United States Children with Atopic Dermatitis: A Narrative Review of the Literature

Approximately 13% of United States (US) children have atopic dermatitis (AD), also known as eczema. AD is a chronic skin condition associated with significant burdens on quality of life and both individual and overall health-care system costs. The pathogenesis of AD is considered to be multifactorial, with biologic factors such as family history and genetics often reported as influencing risk. Some lesser discussed determinants of AD prevalence and severity are sociocultural, such as race/ethnicity, neighborhood, housing type, income level, and family structure. While several factors appear to contribute to disparities in childhood AD, black or African American race/ethnicity most significantly predicts AD prevalence, severity, disease control, access to care, and family impact. There is a shortage of research related to disparities in AD, an important topic considering the large percentage of families that are affected by the disease. This article is a narrative literature review of sociocultural influences on AD disparities in US children. The purpose of this review is to increase awareness of these important risk factors and to suggest related, future areas of research that may positively impact overall outcomes in children with AD. Much work remains to be done in order to ensure equitable care and outcomes among all children with AD.

The role of bacterial skin infections in atopic dermatitis: expert statement and review from the International Eczema Council Skin Infection Group

Patients with atopic dermatitis (AD) have an increased risk of bacterial skin infections, which cause significant morbidity and, if untreated, may become systemic. Staphylococcus aureus colonizes the skin of most patients with AD and is the most common organism to cause infections. Overt bacterial infection is easily recognized by the appearance of weeping lesions, honey‐coloured crusts and pustules. However, the wide variability in clinical presentation of bacterial infection in AD and the inherent features of AD – cutaneous erythema and warmth, oozing associated with oedema, and regional lymphadenopathy – overlap with those of infection, making clinical diagnosis challenging. Furthermore, some features may be masked because of anatomical site‐ and skin‐type‐specific features, and the high frequency of S. aureus colonization in AD makes positive skin swab culture of suspected infection unreliable as a diagnostic tool. The host mechanisms and microbial virulence factors that underlie S. aureus colonization and infection in AD are incompletely understood. The aim of this article is to present the latest evidence from animal and human studies, including recent microbiome research, to define the clinical features of bacterial infections in AD, and to summarize our current understanding of the host and bacterial factors that influence microbial colonization and virulence.

Epidemiology, Diagnosis, and Treatment of Atopic Dermatitis in the Developing Countries of Asia, Africa, Latin America, and the Middle East: A Review

Atopic dermatitis (AD), the leading cause of skin-related burden of disease worldwide, is increasing in prevalence in developing countries of Asia, Africa, Latin America, and the Middle East. Although AD presents similarly across racial and ethnic groups as chronic and relapsing pruritic eczematous lesions, some features of the disease may be more or less prominent in patients with darker skin. Despite a similar presentation, consistent diagnostic criteria and consistent treatment guidelines are lacking. Because of these and other challenges, adherence to treatment guidelines is difficult or impossible. Previous studies have stated that many patients with AD receive ineffective or inappropriate care, such as oral antihistamines, oral corticosteroids, or traditional medicines, if they are treated at all; one study showed that approximately one-third of patients received medical care for their dermatologic condition; of those, almost three-quarters received inappropriate or ineffective treatment. In addition, other challenges endemic to developing countries include cost, access to care, and lack of specialists in AD. Furthermore, most of the available diagnostic criteria and treatment guidelines are based on European and North American populations and few clinical trials report the racial or ethnic makeup of the study population. Drug pharmacokinetics in varying ethnicities and adverse effects in different skin physiologies are areas yet to be explored. The objective of this review is to describe the diagnosis, treatment, and management of AD in developing countries in Asia, Africa, Latin America, and the Middle East; to discuss the differences among the countries; and to establish the unmet needs of patients with AD in them. The unmet medical need for treatment of AD in developing countries can be addressed by continuing to train medical specialists, improve access to and affordability of care, and develop new and effective treatments.Funding Pfizer Inc.

By protecting against cutaneous inflammation, epidermal pigmentation provided an additional advantage for ancestral humans

Pigmentation evolved in ancestral humans to protect against toxic, ultraviolet B irradiation, but the question remains: "what is being protected?" Because humans with dark pigmentation display a suite of superior epidermal functions in comparison with their more lightly pigmented counterparts, we hypothesized and provided evidence that dark pigmentation evolved in Africa to support cutaneous function. Because our prior clinical studies also showed that a restoration of a competent barrier dampens cutaneous inflammation, we hypothesized that resistance to inflammation could have provided pigmented hominins with yet another, important evolutionary benefit. We addressed this issue here in two closely related strains of hairless mice, endowed with either moderate (Skh2/J) or absent (Skh1) pigmentation. In these models, we showed that (a) pigmented mice display a markedly reduced propensity to develop inflammation after challenges with either a topical irritant or allergen in comparison with their nonpigmented counterparts; (b) visible and histologic evidence of inflammation was paralleled by reduced levels of pro-inflammatory cytokines (i.e., IL-1α and INFα); (c) because depigmentation of Skh2/J mouse skin enhanced both visible inflammation and pro-inflammatory cytokine levels after comparable pro-inflammatory challenges, the reduced propensity to develop inflammation was directly linked to the presence of pigmentation; and (d) furthermore, in accordance with our prior work showing that pigment production endows benefits by reducing the surface pH of skin, acidification of albino (Skh1) mouse skin also protected against inflammation, and equalized cytokine levels to those found in pigmented skin. In summary, pigmentation yields a reduced propensity to develop inflammation, consistent with our hypothesis that dark pigmentation evolved in ancestral humans to provide a suite of barrier-linked benefits that now include resistance to inflammation.

Common Skin Disorders in Pediatric Skin of Color

Children with skin of color represent a large proportion of the pediatric population. There are numerous skin conditions that commonly occur in this population, including but not limited to acne, atopic dermatitis, pityriasis alba, tinea versicolor, progressive macular hypomelanosis, traction alopecia, and confluent and reticulated papillomatosis. This article highlights the clinical presentations of these conditions in skin of color and briefly addresses pathophysiology and treatment modalities.

Efficacy and Safety of Crisaborole Ointment, 2%, for the Treatment of Mild-to-Moderate Atopic Dermatitis Across Racial and Ethnic Groups

Background

Atopic dermatitis is highly prevalent in black/African American, Asian, and Hispanic patients, making assessment of these populations in clinical trials important. Crisaborole ointment, 2%, is a nonsteroidal phosphodiesterase 4 inhibitor for the treatment of mild-to-moderate atopic dermatitis. In two pivotal phase III clinical trials in patients aged ≥ 2 years, crisaborole was superior to vehicle in reducing global disease severity. The most common treatment-related adverse event was application site pain.

Objective

The objective of this study was to investigate the efficacy and safety of crisaborole according to patient race and ethnicity.

Methods

A pooled post hoc analysis by race and ethnicity of the two pivotal trials and a safety extension trial was performed. Race included white or nonwhite (encompassing Asian/native Hawaiian/other Pacific Islander, black/African American, and other/American Indian/Alaskan native); ethnicity included Hispanic/Latino or not Hispanic/Latino.

Results

In white, nonwhite, Hispanic/Latino, and not Hispanic/Latino groups at day 29, more crisaborole- than vehicle-treated patients achieved improvements in global disease severity [Investigator’s Static Global Assessment of clear/almost clear with a ≥ 2-grade improvement (white: 33.5% vs. 22.3%, nominal p < 0.001; nonwhite: 30.0% vs. 21.3%, nominal p < 0.05; Hispanic/Latino: 35.4% vs. 18.2%, nominal p < 0.01; not Hispanic/Latino: 31.3% vs. 22.8%, nominal p < 0.01)]. Crisaborole treatment also improved atopic dermatitis signs/symptoms and quality of life. Frequency of crisaborole-related adverse events was 7.1–8.5% in the pivotal trials.

Conclusion

Across races and ethnicities, crisaborole demonstrated efficacy for the treatment of mild-to-moderate atopic dermatitis, with a low frequency of treatment-related adverse events.

Electronic supplementary material

The online version of this article (10.1007/s40257-019-00450-w) contains supplementary material, which is available to authorized users.

African American ancestry contribution to asthma and atopic dermatitis

OBJECTIVE

Asthma and atopic dermatitis (AD) are complex diseases with striking disparities across racial and ethnic groups, which may be partly attributable to genetic factors. Here we summarize current knowledge from asthma and AD genome-wide association studies (GWAS) and pharmacogenetic studies in African ancestry populations.

DATA SOURCES

GWAS catalog; PUBMed.

STUDY SELECTIONS

GWAS catalog studies with trait annotations "asthma" and "atopic eczema" and African ancestry individuals in the discovery dataset; the recent CAAPA asthma GWAS; reports on pharmacogenetic studies in asthma and AD.

RESULTS

Although GWASs have revolutionized gene discovery for multiple complex traits, African Americans continue to be severely underrepresented in sufficiently powered genetics studies. Indeed, of the 16 asthma and 21 AD loci that reached genomewide significance in Europeans, very few have replicated in African ancestry populations. Challenges in comparing results from European vs African ancestry cohorts include modest sample size, differences in risk allele frequency, effect size, correlation between genetic variants, and environmental exposure in evolutionary history. African Americans also constitute a small percentage of dermatological and respiratory-focused clinical trials. Pharmacogenetic studies have similarly been focused largely on non-Hispanic whites, despite compelling evidence that genetic variation from different ancestral backgrounds may alter therapeutic efficacy of asthma and AD drugs.

CONCLUSION

Large-scale genetic studies of asthma and AD in African Americans are essential to reduce research and health disparities and empower scientific discoveries.

Racial differences in atopic dermatitis

OBJECTIVE

To summarize studies investigating ethnical and racial differences in atopic dermatitis (AD) epidemiology, clinical features, and skin and blood phenotypes.

DATA SOURCES

PubMed literature review (years 2000-2018).

STUDY SELECTIONS

Articles discussing primarily human disease.

RESULTS

Higher overall rates of AD were found in Africa and Oceania as opposed to India and Northern and Eastern Europe. In the United States, AD prevalence was found to be higher in African American (19.3%) compared with European American (16.1%) children. Although several studies have consistently found FLG loss-of-function mutations in up to 50% of European and 27% of Asian patients with AD, FLG mutations were 6 times less common in African American than in European American patients, even in patients with severe AD. Thus, FLG mutations seem to play less a pathogenic role in patients of African origin than in individuals of European or Asian ancestry. The immune phenotype of all ethnic groups was characterized by strong TH2 activation, but important differences in immune polarization exist among the different ethnicities. Asian patients with AD had stronger TH17/TH22 activation than African American and European American patients with AD, whereas African American patients had the highest serum IgE levels among all groups, while largely lacking TH1 and TH17 activation.

CONCLUSION

AD is a heterogeneous disease that has differences among various ethnic and racial groups, which might be important for the development of future, targeted treatments and for personalized medicine approaches.

Treatment-resistant prurigo nodularis: challenges and solutions

Prurigo nodualris (PN) is a chronic condition with highly pruritic, hyperkeratotic papules or nodules arising in the setting of chronic pruritus. While PN may serve as a phenotypic presentation of several underlying conditions such as atopic dermatitis, chronic kidney disease-related pruritus, and neurological diseases, it represents a distinct clinical entity that may persist despite the removal of the underlying cause, if one is identified. Neuronal proliferation, eosinophils, mast cells, and small-fiber neuropathy play a role in the production of pruritus in PN, although the exact mechanism has not yet been established. Identifying an underlying cause, if present, is essential to prevent recurrence of PN. Due to often present comorbidities, treatment is typically multimodal with utilization of topical and systemic therapies. We performed a PubMed/MEDLINE search for PN and present a review of recent developments in the treatment of PN. Treatment typically relies on the use of topical or intralesional steroids, though more severe or recalcitrant cases often necessitate the use of phototherapy or systemic immunosuppressives. Thalidomide and lenalidomide can both be used in severe cases; however, their toxicity profile makes them less favorable. Opioid receptor antagonists and neurokinin-1 receptor antagonists represent two novel families of therapeutic agents which may effectively treat PN with a lower toxicity profile than thalidomide or lenalidomide.

Atopic dermatitis in African American patients is TH2/TH22-skewed with TH1/TH17 attenuation

BACKGROUND

African Americans (AA) are disproportionately impacted by atopic dermatitis (AD), with increased prevalence and therapeutic challenges unique to this population. Molecular profiling data informing development of targeted therapeutics for AD are derived primarily from European American (EA) patients. These studies are absent in AA, hindering development of effective treatments for this population.

OBJECTIVE

We sought to characterize the global molecular profile of AD in the skin of AA patients as compared with that of EA AD and healthy controls.

METHODS

We performed RNA-Seq with reverse transcription polymerase chain reaction validation and immunohistochemistry studies in lesional and nonlesional skin of AA and EA AD patients vs healthy controls.

RESULTS

African American AD lesions were characterized by greater infiltration of dendritic cells (DCs) marked by the high-affinity immunoglobulin E (IgE) receptor (FcεR1+) compared with EA AD (P < .05). Both AD cohorts showed similarly robust up-regulation of Th2-related (CCL17/18/26) and Th22-related markers (interleukin [IL]-22, S100A8/9/12), but AA AD featured decreased expression of innate immune (tumor necrosis factor [TNF], IL-1β), Th1-related (interferon gamma [IFN-γ], MX1, IL-12RB1), and Th17-related markers (IL-23p19, IL-36G, CXCL1) vs EA AD (P < .05). The Th2 (IL-13) and Th22-related products (IL-22, S100A8/9/12) and serum IgE were significantly correlated with clinical severity (Scoring of Atopic Dermatitis [SCORAD]) in AA. Fillagrin (FLG) was exclusively down-regulated in EA AD, whereas loricrin (LOR) was down-regulated in both AD cohorts and negatively correlated with SCORAD in AA.

CONCLUSION

The molecular phenotype of AA AD skin is characterized by attenuated Th1 and Th17 but similar Th2/Th22-skewing to EA AD. Our data encourages a personalized medicine approach accounting for phenotype-specific characteristics in future development of targeted therapeutics and clinical trial design for AD.

A minimally invasive tool to study immune response and skin barrier in children with atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) affects children of all skin types. Most research has focused on light skin types. Studies investigating biomarkers in people with AD with dark skin types are lacking.

OBJECTIVES

To explore skin barrier and immune response biomarkers in stratum corneum (SC) tape strips from children with AD with different skin types.

METHODS

Tape strips were collected from lesional and nonlesional forearm skin of 53 children with AD and 50 controls. We analysed 28 immunomodulatory mediators, and natural moisturizing factors (NMF) and corneocyte morphology.

RESULTS

Interleukin (IL)-1β, IL-18, C-X-C motif chemokine (CXCL) 8 (CXCL8), C-C motif chemokine ligand (CCL) 22 (CCL22), CCL17, CXCL10 and CCL2 were significantly higher (P < 0·05) in lesional AD skin compared with nonlesional AD skin; the opposite trend was seen for IL-1α. CXCL8, CCL2 and CCL17 showed an association with objective SCORing Atopic Dermatitis score. NMF levels showed a gradual decrease from healthy skin to nonlesional and lesional AD skin. This gradual decreasing pattern was observed in skin type II but not in skin type VI. Skin type VI showed higher NMF levels in both nonlesional and lesional AD skin than skin type II. Corneocyte morphology was significantly different in lesional AD skin compared with nonlesional AD and healthy skin.

CONCLUSIONS

Minimally invasive tape-stripping is suitable for the determination of many inflammatory mediators and skin barrier biomarkers in children with AD. This study shows differences between children with AD with skin type II and skin type VI in NMF levels, suggesting that some aspects of pathophysiological mechanisms may differ in AD children with light versus dark skin types.