Adult-onset atopic dermatitis is associated with a distinct phenotype

Adult-onset atopic dermatitis (AD) has been reported to occur commonly. However, little is known about the risk factors and clinical characteristics of adult-onset AD. We performed a prospective study of 260 adults with AD to determine the associations and clinical characteristics of adult-onset disease. Personal and family history of atopic disease, signs and symptoms of AD were assessed by questionnaire and physical exam. Overall, 108 (45.4%) reported AD-onset during adulthood and 75 (28.8%) after age 50 yrs. Adult- vs. childhood-onset AD was associated with birthplace outside the US (chi square, P=0.02), but not sex, race/ethnicity, current smoking or alcohol consumption (P≥0.14); and significantly decreased personal or family history of asthma, hay fever and food allergy (P≤0.002 for all). Adult-onset AD was associated with lower Eczema Area and Severity Index (Mann-Whitney U test, P=0.008), Scoring AD (P=0.009), body surface area (P=0.003), but not Numerical Rating Scale-itch and sleep or Patient Oriented Eczema Measure (P≥0.38 for all). Latent Class Analysis identified 3 classes: 1. high probability of xerosis and intermediate probabilities of flexural or hand dermatitis; 2. high probability of xerosis, flexural, head, neck and hand dermatitis; 3. highest probabilities of all signs and symptoms. Adult-onset AD was associated with class 1 (multivariate logistic regression; aOR [95% CI]: 4.42 [1.16-16.89]) and 2 (3.25 [1.22-8.65]). In conclusion, adults with AD have high rates of self-reported adult-onset and distinct phenotypes.