Prevalence and incidence of comorbidities in patients with atopic dermatitis, psoriasis, alopecia areata, and vitiligo using a Japanese claims database.

Atopic dermatitis, psoriasis, alopecia areata, and vitiligo have been associated with comorbid conditions, including infections, malignancies, and cardiovascular diseases. This study evaluated the prevalence and incidence rates of these comorbidities in patients from Japan. This retrospective cohort study used data collected from the JMDC claims database between June 2013 and December 2020. Patients with a diagnosis of atopic dermatitis, psoriasis, alopecia areata, or vitiligo were matched (1:1) by age, sex, and index month with individuals with no claims records for atopic dermatitis, psoriasis, alopecia areata, or vitiligo diagnosis. Data included 691 338, 51 988, 43 692, and 8912 patients in the atopic dermatitis, psoriasis, alopecia areata, and vitiligo cohorts, respectively, and matched controls. The most prevalent comorbidities in the atopic dermatitis cohort versus matched controls included allergic rhinitis (47% vs 37%), conjunctivitis (33% vs 23%), asthma (27% vs 20%), viral infection (22% vs 15%), and acne (11% vs 3%). Incidence rates per 100 000 person-years of comorbidities in the atopic dermatitis cohort versus matched controls were: venous thromboembolism, 51.4 (95% confidence interval [CI], 48.3-54.7) versus 31.7 (95% CI, 29.2-34.2); lymphoma, 13.8 (95% CI,12.2-15.6) versus 5.7 (95% CI, 4.7-6.8); cutaneous T-cell lymphoma, 1.6 (95% CI, 1.1-2.2) versus 0.1 (95% CI, 0.0-0.4); and herpes zoster, 740.9 (95% CI, 728.8-753.1) versus 397.6 (95% CI, 388.9-406.6). Similar trends were observed in the psoriasis versus nonpsoriasis cohorts, with 95% CIs mostly overlapping for alopecia areata and vitiligo cohorts versus controls. Overall, patients from Japan with dermatologic diseases have a higher prevalence and incidence of certain health conditions, particularly venous thromboembolism, lymphoma, and infections in patients with atopic dermatitis and psoriasis, compared with individuals without these dermatologic diseases.