Atopic dermatitis in adults: a population-based study in Finland

Background The prevalence of atopic dermatitis (AD) has increased, but studies in adult or elderly populations are sparse. Methods We investigated 12-month and lifetime prevalences of AD in the Finnish adult population >= 30 years of age and analyzed living environment factors, socioeconomic factors, lifestyle-related factors, and serum vitamin D levels for their associations with AD in a national health examination survey. Results The lifetime prevalence was 21.9% and 12-month prevalence 10.1%. The highest prevalence (lifetime 28.6%, 12-month 15.4%) was seen in subjects 30-39 years of age. Prevalence decreased with age. Subjects with highly educated parents were more likely to have active AD, though there was no effect of higher education in subjects themselves. Younger age and being an ex-smoker were associated with active AD. Female sex and daily smoking increased the risk in subjects 30-49 years of age. There was no dose-response relationship to serum vitamin D levels and no association with the living environment. Conclusions Our data show that the number of adult patients with atopic dermatitis has grown and prevalence numbers of AD in Finnish adults are among the highest reported. Together with the aging of the society, the burden of AD is not limited to childhood.