IMPORTANCE: Previous studies found conflicting results as to whether atopic dermatitis (AD) is increased in patients with vitiligo and alopecia areata (AA). OBJECTIVE: To compare the prevalence of AD between patients with either vitiligo or AA and those without these disorders by performing a meta-analysis of observational studies. DATA SOURCES: MEDLINE, EMBASE, Cochrane Library, Google Scholar, and a manual search of 12 additional journals between 1946 and April 5, 2014. STUDY SELECTION: Observational studies published in any language that compared the prevalence of AD among patients with and without either vitiligo or AA. DATA EXTRACTION AND SYNTHESIS: Data were extracted by 2 independent investigators. Quality of evidence was assessed using the Newcastle-Ottawa Scale and Methodological Evaluation of Observational Research checklist. A meta-analysis of studies assessing AD, vitiligo, and/or AA was performed using a fixed-effects model to estimate pooled odds ratios (ORs). Subset analyses were performed for childhood vs adult-onset vitiligo and alopecia totalis or alopecia universalis vs patchy alopecia. MAINOUTCOMESANDMEASURES: Self-reported and/or physician-diagnosed AD, vitiligo, and AA. RESULTS;In total, 16 studies of vitiligo and 17 studies of AA were included in the review. In the pooled analysis of the studies that included control patients without vitiligo (n = 2) and control patients without AA (n = 3), patients with vitiligo (Cochran-Mantel-Haenszel OR, 7.82; 95% CI, 3.06-20.00, P <.001) or AA (OR, 2.57; 95% CI, 2.25-2.94, P <.001) had significantly higher odds of AD than did control patients without these disorders. Pooled analysis of 3 studies found higher odds of AD in patients with early-onset vitiligo (<12 years) compared with those with late-onset vitiligo (OR, 3.54; 95% CI, 2.24-5.63, P <.001). Pooled analysis of 4 studies found higher odds of AD in patients with alopecia totalis or alopecia universalis compared with those with patchy alopecia (OR, 1.22; 95% CI, 1.01-1.48, P =.04). CONCLUSIONS AND RELEVANCE: Patients with either vitiligo, especially early-onset disease, or AA, especially alopecia totalis or alopecia universalis, have significantly increased risk for AD.
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