Patients with moderate-to-severe alopecia areata (AA) had higher prevalence and incidence of atopic dermatitis (AD) comorbidity and higher prevalence of moderate-to-severe AD than those with mild AA in a study presented this month at the Revolutionizing Alopecia, Vitligo, and Eczema (RAVE) Conference in Chicago, Illinois.

Previous studies had shown that patients with vs without AA have a higher risk of developing AD. However, the real-world prevalence and incidence of moderate-to-severe AD in patients with AA were not well characterized.

“Prevalence and incidence of atopic dermatitis in patients with alopecia areata in the United States: a population-based study,” presented by Arash Mostaghimi, MD, MPH, FAAD, and colleagues, involved a retrospective analysis evaluating claims from the Merative Marketscan Commercial Claims and Encounters database. Among the 10,863 eligible patients identified with AA, the prevalence within 5 years pre-index date was 3.1% for any AD and 2.3% for moderate-to-severe AD. Among patients with moderate-to-severe AA, the prevalence was 4.8% for any AD and 4.2% for moderate-to-severe AD. The prevalence of any AD any time pre-index among patients with AA and moderate-to-severe AA was 11.9% and 14.6%, respectively.

“AD incidence at follow-up was 4 per 1000 person-years in patients with mild AA, 7 per 1000 person-years for moderate-to-severe AA, and 6 per 1000 person-years for very severe AA,” the study noted. “Mean (SD) time to AD diagnosis after AA index date was 2.1 (1.7) years for patients with mild AA, 2.0 (1.7) years for moderate-to-severe AA, and 2.0 (1.7) years for very severe AA. Risk of developing AD was greater in patients with moderate-to-severe vs mild AA (adjusted hazard ratio 1.63 [95% CI 1.01, 2.64]).”