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.     

SCORAD 75: a new metric for assessing treatment outcomes in atopic dermatitis

Objective The scoring atopic dermatitis (SCORAD) is a well‐established severity‐scoring tool for atopic dermatitis (AD). Dead Sea climatotherapy (DSC) is a natural selective balneo‐phototherapy utilized for many years to treat severe AD. The study’s goal was to evaluate the impact of DSC on AD patients through assessment of SCORAD scores and to identify parameters associated with greater improvement. Methods The files of 78 European patients (37 male patients and 41 female patients, mean age 37.8 years) with AD undergoing DSC were included in this retrospective study. Three sub‐groups were delineated based on disease severity (as determined using the SCORAD). Demographic and clinical parameters as well as treatment characteristics – maximal and cumulative sun exposure doses – were recorded. SCORAD values were again recorded for assessment of treatment response. SCORAD 75 was defined as ≥75% decrease in SCORAD values following therapy. Statistical analysis including logistic regression models was used in multivariable analysis. Results After an average of 30 days of treatment, mean SCORAD values dropped from 50.5 to 11 (76.7%, P < 0.001). 64.1% of all patients, regardless of sub‐group, reached SCORAD 75, whereas 78.9% of patients with severe disease achieved this result. In a multivariate logistic regression, factors associated with achieving SCORAD 75 were maximal sun exposure, family history of AD and age at disease onset (P = 0.002, P = 0.009 and P = 0.040 respectively). Conclusion Dead Sea climatotherapy is a particularly effective treatment method for the sub‐population of adults with severe AD. The SCORAD 75 can be useful for defining sub‐populations in which treatment is more likely to be successful.     

The role of the skin microbiome in atopic dermatitis: a systematic review

Dysbiosis is a hallmark of atopic dermatitis (AD). The composition of skin microbiome communities and the causality of dysbiosis in eczema have not been well established. The objective of this review is to describe the skin microbiome profile in AD and address whether there is a causal relationship between dysbiosis and AD. The protocol is registered in PROSPERO (CRD42016035813). We searched PubMed, Embase, Scopus and ClinicalTrials.gov for primary research studies applying culture‐independent analysis on the microbiome on AD skin of humans and animal models. Two authors independently screened the full text of studies for eligibility and assessed risk of bias. Because of heterogeneity no quantitative synthesis was done. Of 5735 texts, 32 met the inclusion criteria (17 published: 11 human and six animal studies). The studies varied in quality and applied different methodology. The skin in AD had low bacterial diversity (lowest at dermatitis‐involved sites) and three studies showed depletion of Malassezia spp. and high non‐Malassezia fungal diversity. The relative abundance of Staphylococcus aureus and Staphylococcus epidermidis were elevated and other genera were reduced, including Propionibacterium. A mouse study indicated that dysbiosis is a driving factor in eczema pathogenesis. The data are not sufficiently robust for good characterization; however, dysbiosis in AD not only implicates Staphylococcus spp., but also microbes such as Propionibacterium and Malassezia. A causal role of dysbiosis in eczema in mice should encourage future studies to investigate if this also applies to humans. Other important aspects are temporal dynamics and the influence of methodology on microbiome data.     

A comparative study of childhood psoriasis and atopic dermatitis and greater understanding of the overlapping condition, psoriasis-dermatitis

Background and Objectives: Psoriasis (Pso) in children may be confused clinically with atopic dermatitis (AD) and, indeed, the two conditions may co‐exist. The aim of this study was to determine historical and clinical features that are different in paediatric Pso and AD and to describe children who have features of both: psoriasis‐dermatitis overlap (PD). Methods: Children with features of psoriasis or eczema, or both, who were referred to paediatric outpatients and/or private rooms were evaluated. Data were collected from 170 consecutive children aged less than 12 years between July 2011 and November 2011. Participants were classified by described criteria as having Pso (n = 64), AD (n = 62) or PD (n = 44). Results: Only 9.4% of children with Pso were correctly diagnosed by the referring doctor. Children with Pso relative to AD were more likely to have had a history of scaly scalp and nappy rash in infancy, a family history of psoriasis, current scalp and periauricular rashes, defined, patchy plaque morphology and papulosquamous rashes not typical of adult psoriasis on extensor elbows and knees. Children with PD had features of both but presented most often as typical paediatric psoriasis combined with flexural eczema. Children with Pso and PD responded well to specific treatment strategies for psoriasis, including potent topical corticosteroids (TCS), calcipotriol and phototherapy. Both Pso and PD tended to require more potent TCS than AD to achieve disease suppression. Conclusion: We found that Pso and PD in children both differ clinically from AD and have identified historical and clinical features that characterise childhood Pso.     

Distinct SPINK5 and IL-31 polymorphisms are associated with atopic eczema and non-atopic hand dermatitis in Taiwanese nursing population

Abstract: The term ‘hand dermatitis’ describes inflammatory skin condition localized to the hands. Nurses working at hospital settings are prone to develop hand dermatitis. The current study aimed to evaluate whether certain genetic polymorphisms were associated with the development of atopic eczema or non‐atopic hand dermatitis in Taiwanese population. Nurses of Kaohsiung Medical University Hospital were recruited. Atopic eczema, non‐atopic hand dermatitis and normal control groups were identified. The serine protease inhibitor Kazal type 5 (SPINK5), filaggrin and interleukin‐31 (IL‐31) gene variants were compared between the diseased and control groups. Our results showed that rs2303070 T allele of SPINK5 (assuming recessive model; OR = 3.58, 95% CI 1.63–7.84; P = 0.0014) and rs7977932 G allele of IL‐31 (assuming recessive model; OR = 18.25, 95% CI = 3.27–101.94; P = 0.0009) were associated with increased risks of developing atopic eczema, while rs6892205 G allele of SPINK5 (assuming dominant model; OR = 3.79, 95% CI 1.55–9.28; P = 0.0036) was associated with the development of non‐atopic hand dermatitis. In summary, our results showed that distinct SPINK5 and IL‐31 gene variants were associated with the development of atopic eczema and non‐atopic hand dermatitis. The barrier function, particularly those regulated by SPINK5, may play an important role in the development of both atopic eczema and non‐atopic hand dermatitis.     

Association between non‐atopic hand eczema and interleukin‐13 gene polymorphism in Taiwanese nursing population

Chronic hand eczema is an important occupational skin disease with atopic dermatitis (AD) and wet work being the most important risk factors. This study was launched to analyse the potential association between AD‐related inflammation genes and development of non‐atopic hand eczema among nurses in University Hospital. Atopic eczema, non‐atopic hand dermatitis and control groups were identified. The association between occurrence of non‐atopic hand eczema and interleukin (IL)‐13, IL‐4 and IL‐5 gene variants was analysed. IL13 rs20541 A allele [assuming recessive model; odds ratio (OR) = 3.38, 95% CI: (1.63–7.00)] showed association with development of non‐atopic hand eczema. Additive score analyses showed combination of this gene variant with previously identified risk factors including certain SPINK5 polymorphism and more than 10 years of work experience conferred highest risk for development of non‐atopic hand eczema. As non‐atopic hand eczema made up significant portion of occupational skin diseases, further studies should be focused on this commonly encountered skin condition.     

Salivary Cortisol Response to Stress in Young Children with Atopic Dermatitis

Abstract: Poor responsiveness of the hypothalamic–pituitary–adrenal (HPA) axis under stress may be one explanation for stress‐induced exacerbation of atopic dermatitis (AD) symptoms. In previous studies, children and adults with AD showed attenuated salivary cortisol responses to psychosocial stress, suggesting hyporesponsiveness of the HPA axis, but few studies have been conducted in young children, who are vulnerable to systemic side effects of topical corticosteroid (TCS) therapy. We evaluated whether salivary cortisol responses to the stress of venipuncture in young children with AD were related to the severity of AD or performance of TCS therapy. We studied 38 young children with AD (median age 16.5 mos, range 3–66 mos) being treated at our outpatient unit. Patients were divided into three groups according to the scoring of atopic dermatitis index: mild (n = 12), moderate (n = 14), and severe (n = 12). To evaluate the responsiveness of the HPA axis to stress, salivary cortisol was determined before and after venipuncture. Salivary cortisol responsiveness to stress correlated negatively with severity of AD (p = 0.048) but not with previous use of TCS (p = 0.43) in young children with AD. Our findings suggest that the disease activity of AD, rather than TCS use, is responsible for HPA axis dysfunction in children with AD.     

Clinical features of atopic dermatitis in a hospital‐based setting in China

Background Atopic dermatitis (AD) is a chronic relapsing inflammatory skin disease. There have been few detailed reports of the clinical evaluation of Chinese patients with AD. Objectives To give a profile of the clinical features of Chinese AD patients in a university hospital setting. Methods A total of 1008 cases met Hanifin and Rajka diagnostic criteria of AD were recruited at Xinhua Hospital, Shanghai Jiaotong University School of Medicine, China. Results In our survey, 22.7% patients were mild, 66.6% were moderate and 10.7% were severe according to the SCORAD index. Both the frequency and severity of the male patients were slightly higher. The frequency of asthma among the AD patients was 16.7% and it was increased with the age (χ² = 205.20, P = 0.000). The frequencies of objective minor signs were demonstrated with age‐related changes. Besides, three localized variants including eyelid eczema (49.8%), scalp dermatitis (49.7%), infra‐auricular and retroauricular fissuring (44.8%) were commonly observed, especially in the infantile phase (P < 0.01). It was showed significant differences in serum total immunoglobulin E (IgE) and eosinophil cationic protein (ECP) levels of different age groups. The positive rate of Phadiatop was raised after 3 years old and that of the common food allergens were decreased after 6 years old. Conclusions More males than females had ongoing AD in our survey. Most AD debuted in the first year of the cases. High incidence of the three clinical signs: eyelid eczema, scalp dermatitis and infra‐auricular and retroauricular fissuring among the patients suggests it can be a potential valuable diagnostic clue to AD.     

Impaired sweating function in adult atopic dermatitis: results of the quantitative sudomotor axon reflex test

Summary Background Impaired sweating is thought to be a cause of barrier dysfunction in atopic dermatitis (AD). Objectives To examine the sweating function in AD in a quantitative manner. Methods We investigated the sweating response of lesional and non‐lesional skin of adult patients with AD by a quantitative sudomotor axon reflex test in which the axon reflex is stimulated by acetylcholine iontophoresis. Sweat volume on the volar aspect of the forearm was measured in 18 adult patients with AD and in 40 non‐atopic controls; five patients with Sjögren's syndrome were also studied as disease comparators. We also evaluated the sweating function in four AD patients after topical corticosteroid therapy. Latency time, direct (DIR) sweat volume and axon reflex‐mediated indirect (AXR) sweat volume were the variables studied. Results The latency time in AD patients was significantly prolonged and AXR sweat volume significantly reduced compared with those in non‐atopic control subjects. The latency time and AXR sweat volume of lesional AD skin were significantly more prolonged and reduced, respectively, than those of non‐lesional skin. In contrast, the DIR sweat volume of lesional or non‐lesional AD skin induced by direct stimulation with acetylcholine was only slightly reduced when compared with that in non‐atopic controls. Latency time and sweat volumes of lesional and non‐lesional AD skin improved after topical corticosteroid therapy. Conclusions These results suggest that the impaired sweat response in AD is attributable to an abnormal sudomotor axon reflex, which is reversed by topical corticosteroid administration.     

Topical acidic cream prevents the development of atopic dermatitis‐ and asthma‐like lesions in murine model

Long‐standing or repeated skin barrier damage followed by atopic dermatitis (AD) is the initial step of the atopic march that eventually progresses to respiratory allergies. Maintenance of an acidic pH in the stratum corneum (SC) is an important factor for normal skin barrier function. We performed this study to determine whether an oxazolone (Ox)‐induced AD murine model can develop airway inflammation by topical application and nasal inhalation of a house dust mite, Dermatofagoides pteronyssinus (Dp), which is a novel ‘atopic march animal model’, and whether an acidic SC environment, made by repeated application of acidic cream, can interrupt this atopic march. During repeated treatment with Ox and Dp to make an atopic march murine model, acidic cream (pH 2.8) and neutral cream (pH 7.4) adjusted by citric acid and sodium hydroxide mixed with vehicle were applied twice daily. Repeated treatment with Ox and Dp to hairless mice induced AD‐like skin lesions followed by respiratory allergy, defining it as an atopic march model. Acidic cream inhibited the occurrence of respiratory allergic inflammation as well as AD‐like skin lesions. These results indicate that a novel atopic march animal model can be developed by repeated topical and nasal treatments with house dust mite on Ox‐induced AD mice and that the acidification of SC could be a novel intervention method to block the atopic march.     

Moderate correlation between quality of life and disease activity in adult patients with atopic dermatitis

Background Studies assessing the relationship between disease activity and quality of life (QoL) in adults with atopic dermatitis (AD), before and after therapy are lacking. The relation between disease activity and QoL in AD patients was evaluated before (t = 0) and after 6 weeks (t = 6) of treatment with cyclosporin 5 mg/kg. Methods In 54 patients with severe AD, disease activity was assessed using objective Scoring Atopic Dermatitis index (SCORAD), Six Area Six Sign Atopic Dermatitis (SASSAD), ‘rule of nines’ extent score and serum levels of thymus and activation‐regulated chemokine (TARC). Patients filled out the Dermatology Life Quality Index (DLQI). To study the relation between disease activity and QoL, correlations were calculated and regression analysis was performed. Results At t = 0 there was a small, non‐significant correlation between the DLQI and the objective SCORAD, ‘rule of nines’ or serum TARC levels. At t = 6 the objective SCORAD, serum TARC and the ‘rule of nines’ score showed moderate and significant correlations with the DLQI (r = 0.34, P = 0.02; r = 0.31, P = 0.03; r = 0.49, P < 0.001). An individual’s improvement in disease activity (objective SCORAD, SASSAD and ‘rule of nines’) with 10 points was associated with an improvement of 1.3, 1.5 and 1.1 points respectively in DLQI. Conclusions Disease activity correlated better with QoL when disease activity was less severe and disease extent (‘rule of nines’) correlated better with QoL than disease severity. An individual’s improvement of 10 points in disease activity was accompanied by only a small improvement in QoL. Other factors than disease activity may influence QoL in patients with AD.     

Novel filaggrin mutation but no other loss-of-function variants found in Ethiopian patients with atopic dermatitis

Background Filaggrin is a key protein involved in maintaining skin barrier function and hydration. Mutations in the filaggrin gene (FLG) cause ichthyosis vulgaris (IV) and are a major predisposing factor for atopic dermatitis (AD) in individuals of European and Asian descent. It has been proposed that FLG mutations are population specific and a difference in the spectra of mutations between different ancestral groups has been described. However, it is unknown whether FLG mutations in the African population are a causative genetic factor for IV and predispose to AD, or whether other mechanisms are more prominent. Objectives The present aim was to investigate the role of FLG mutations as predisposing factors for IV or AD among individuals from Ethiopia. Methods A case series of Ethiopian patients with AD (n = 103) and IV (n = 7) together with controls (n = 103; subjects without past or present history of AD, dry skin or atopic manifestations) was collected at the outpatient dermatology clinics at ALERT Dermatology Hospital, Tikur Anbessa Hospital and Gondar University Hospital, Ethiopia. AD was diagnosed by a dermatologist using the U.K. Working Party’s diagnostic criteria. The IV diagnosis was based on clinical examination and genetic testing of the steroid sulphatase gene to exclude X‐linked recessive ichthyosis. Patients were studied with direct sequencing (n = 40) and/or allelic discrimination (n = 110). Immunohistochemical analysis was performed for filaggrin expression in the skin of patients (n = 7) and controls (n = 2). Results The Ethiopian patients and controls were genotyped for the four previously described common European FLG null mutations (R501X, 2282del4, S3247X, R2447X) and no carriers were found. In one patient with AD a novel heterozygous 2‐bp deletion, 632del2, leading to a premature stop codon was revealed by direct sequencing. No additional carrier of this deletion or other mutations was found. In addition, no difference in filaggrin expression was detected in AD or IV skin compared with healthy control skin. Conclusions Our results indicate that FLG loss‐of‐function‐variants are less common in patients with IV and AD in the Ethiopian population, suggesting that other factors may be of importance in the pathogenesis in this ethnic group.     

Validez de una encuesta telefónica para determinar la prevalencia y la estacionalidad de la dermatitis atópica en España

BackgroundAtopic dermatitis is a eczematous disease of the skin with onset during childhood and subsequent flares. The UK Working Party (UKWP) defined the diagnostic criteria normally used for atopic dermatitis. The objective of this study was to assess the prevalence of atopic dermatitis according to these criteria.MethodsThis was a 2-phase cross-sectional, epidemiologic computer-assisted telephone survey. Parents of children aged 14 years or less participated in the first phase to determine the prevalence of atopic dermatitis in Spain. In the second phase, 6 months later, parents of children with diagnosis of atopic dermatitis according to the UKWP diagnostic criteria in phase 1 were interviewed to assess seasonal variations in disease activity between the 2 phases.ResultsIn total, 1979 parents participated; 8.6 % of the children (95 % confidence interval, 7.4 %-9.8 %) were diagnosed with atopic dermatitis by telephone. Of these, 49.2 % had a family history of atopy and 41.3 % had been diagnosed with atopic dermatitis by a physician. Diagnosis by the physician and that made by interview agreed in 75.3 % of these cases. Of the factors associated with atopic dermatitis, it was found that increased body temperature, periods of stress, dust, use of/contact with wool or fiber clothes, and use of certain soaps and hygiene products showed seasonal variations.ConclusionsThe estimated prevalence of atopic dermatitis in children between 0 and 14 years old in Spain was 8.6 %. Certain factors associated with disease flares showed seasonal variations.     

Atopic dermatitis and respiratory symptoms in Russian and northern Norwegian school children: a comparison study in two arctic areas and the impact of environmental factors

Background The increase in atopic diseases during recent decades has been related to environmental factors such as indoor and outdoor pollution and the ingestion of certain foods. On the other hand, studies from Eastern Europe (with heavy air pollution) have reported a lower prevalence of atopic diseases and sensitization in their schoolchildren than in children living in Western Europe. Objectives This study compares the frequency of atopic diseases and respiratory symptoms in two geographically close arctic areas and points to possible risk factors for development of the diseases. Methods A total of 1734 schoolchildren (1183 in Nikel and 551 in Sør‐Varanger) were studied using identical, four‐page, self‐administered questionnaires. Results Atopic diseases were reported in 38.7% of Norwegian and in 24.2% of Russian children (P < 0.001). Atopic dermatitis (AD) (23.6% vs 7.9%; P < 0.001) and allergic rhinoconjunctivitis (AR) (20.6% vs 14.7%; P < 0.001) occurred more frequently in Sør‐Varanger, whereas ‘self‐reported’ asthma (12.3% vs 13.1%) was similar in both areas. However, respiratory symptoms such as coughing, wheezing, breathlessness and bronchitis were 3–4 times more frequent in Nikel (P < 0.001). Conclusion This study disproves a previous hypothesis, i.e. that air pollution must be a major risk factor for the development of atopic diseases. Nevertheless, respiratory tract symptoms may be provoked by environmental pollution. Possible explanations for the higher frequency of atopic diseases in Sør‐Varanger may be found in socio‐economic and lifestyle differences between the two populations.     

The millennium criteria for the diagnosis of atopic dermatitis

Abstract: Atopic dermatitis forms an active area of basic and clinical research, where important new knowledge about genetics and immunopathogenesis has surfaced over the past years, and where simultaneous development of new and innovative therapies is under way. However, the inclusion of any patient in an atopic dermatitis study, whether it is on its genetics, pathogenesis or therapy, requires a diagnosis which is irrefutable. Since there is no simple and also no complicated laboratory procedure to reach a diagnosis of atopic dermatitis, different sets of clinical criteria have been developed for the purpose of making the diagnosis uniformly in different studies as well as in different study centers. The most commonly used are Hanifin and Rajka's set of diagnostic features, which have major and minor clinical criteria to be fulfilled in order to establish a diagnosis of atopic dermatitis. Recent developments in the immunology of atopy have clearly established the major abnormality in this syndrome, the preferential production of allergen-specific IgE. In this contribution, it is suggested that the presence of such antibodies in a given patient should be a mandatory criterium for the diagnosis of atopic dermatitis. Such a diagnostic test however establishes a diagnosis of atopic syndrome, not atopic dermatitis. Thus, for atopic dermatitis we have to rely, for the time being, on additional clinical criteria. The clinical features described in the literature are critically evaluated, and it is suggested that in addition to the mandatory presence of allergen-specific IgE, 2 of 3 principal criteria (pruritus, typical morphology and distribution, chronic or chronically relapsing) should be present for such a diagnosis. Finally, the minor features originally described by Hanifin and Rajka and later evaluated by others are revised and divided over 4 subcategories; a) related to subclinical eczema; b) related to dry skin; c) extra skin folds; and d) ophthalmological pathology. They are suggested to be used as additional criteria only, needed when clinical suspicion is high but the new mandatory and principal diagnositic criteria described here are inconclusive. For study purposes, we suggest that the mandatory and principal criteria are sufficient. They are now evaluated and validated in ongoing atopic dermatitis treatment studies.     

Developing drugs for treatment of atopic dermatitis in children (≥3 months to <18 years of age): Draft guidance for industry

Atopic dermatitis is the most common chronic skin disease, and it primarily affects children. Although atopic dermatitis (AD) has the highest effect on burden of skin disease, no high‐level studies have defined optimal therapy for severe disease. Corticosteroids have been used to treat AD since the 1950s and remain the only systemic medication with Food and Drug Administration approval for this indication in children, despite published guidelines of care that recommend against this option. Several clinical trials with level 1 evidence have supported the use of topical treatments for mild to moderate atopic dermatitis in adults and children, but these trials have had little consistency in protocol design. Consensus recommendations will help standardize clinical development and trial design for children. The Food and Drug Administration issues guidance documents for industry as a source for “the Agency's current thinking on a particular subject.” Although they are nonbinding, industry considers these documents to be the standard for clinical development and trial design. Our consensus group is the first to specifically address clinical trial design in this population. We developed a draft guidance document for industry, Developing Drugs for Treatment of Atopic Dermatitis in Children (≥3 months to <18 years of age). This draft guidance has been submitted to the Food and Drug Administration based on a provision in the Federal Register (Good Guidance Practices).     

Comparative efficacy of Hanifin and Rajka''s criteria and the UK working party''s diagnostic criteria in diagnosis of atopic dermatitis in a hospital setting in North India

BACKGROUND: Diagnosis of atopic dermatitis (AD) depends on clinical features because no definitive diagnostic test exists. Criteria proposed by Hanifin and Rajka (Acta Derm Venereol (Stockh) 1980; Suppl 92: 44-47) were acceptable for hospital-based studies but were found not to be suitable for field studies. A UK working party formulated clinical diagnostic criteria that could be used in both hospital and epidemiological settings. Validation studies of the criteria showed widely variable results, probably due to different clinical settings and ethnicity. AIM AND OBJECTIVE: This study was undertaken to validate Hanifin and Rajka's criteria and to assess the comparative efficacy of their criteria and the UK working party's diagnostic criteria in the diagnosis of AD in a hospital setting in North India. SUBJECTS AND METHODS: This study serially included 101 patients with AD and 48 controls of paediatric age group. The study period was from July 2003 to December 2004. RESULTS: Hanifin and Rajka's criteria (sensitivity 96%, specificity 93.75%, positive predictive value 97% (PPV) and negative predictive value (NPV) 91.84%) had a statistical advantage over the UK working party's diagnostic criteria (sensitivity 86%, specificity 95.83%, PPV 97.75% and NPV 76.67%), with a P-value < 0.005.     

Intragenic Copy Number Variation in the Filaggrin Gene in Ethiopian Patients with Atopic Dermatitis

Genetic variants in filaggrin (FLG) involving truncating mutations or intragenic copy number variation are strongly associated with the risk of developing atopic dermatitis (AD) in European and Asian populations. Few loss‐of‐function mutations have been identified in Africans, although an association between FLG copy number variation and AD severity in a small African American cohort has been proposed. We studied the association between FLG copy number and AD in 132 Ethiopians and found no association between AD severity and FLG copy number, suggesting that other, still unidentified genetic factors are of more importance in predisposing Ethiopians to AD.