KYOTO, JAPAN Atopic dermatitis is one of the most common skin diseases in Japanese adults, especially those in their 20s and 30s, according to a first-of-its-kind study.
The high prevalence rates found were quite similar to those earlier reported in an Australian study in which, as in the Japanese study, the diagnosis of adult atopic dermatitis was made by experienced dermatologists. Taken together, these two large studies suggest atopic dermatitis in adults is common and underappreciated, according to Dr. Hidehisa Saeki, a dermatologist at the University of Tokyo.
He reported on 2,943 staff members, aged 2069, at two Japanese medical schools. When they reported for their required annual general health checkup, they were examined by dermatologists who diagnosed atopic dermatitis using Japanese Dermatological Association criteria, which are similar to Hanifin criteria.
This was the first study of adult atopic dermatitis in Japan in which the diagnosis was based upon clinical examination by dermatologists, Dr. Saeki reported at an international investigative dermatology meeting.
The prevalence of atopic dermatitis was 8% in 1,184 women and 5% in 1,759 men. The disease was classified as mild in 79% of cases, moderate in 17%, severe in 3%, and very severemeaning greater than 30% skin area involvement during eruptionsin 1%.
The overall prevalence of atopic dermatitis was 9% among subjects in their 20s, 8% in the 30s, 5% in the 40s, and 3% in participants in their 50s and 60s.
Most affected adults had a history of atopic dermatitis in childhood, Dr. Saeki explained at the meeting of the European Society for Dermatological Research, the Japanese Society for Investigative Dermatology, and the Society for Investigative Dermatology.
Worldwide, there have been few studies of atopic dermatitis in adults, and mostly they relied upon questionnaire surveys. One of the rare exceptions that employed total body examination and dermatologic diagnosis was conducted by investigators at the University of Melbourne, who reported a 7% prevalence of atopic dermatitisquite close to the Japanese figurein 1,457 residents of central Victoria aged 2094 years (Int. J. Dermatol. 1999;38:9018).
Dr. Saeki noted that the Australian and Japanese investigators found many shared trends in adult atopic dermatitis: the prevalence in both countries was higher in women, the prevalence declined with age, and roughly 80% of affected individuals had mild disease.
American dermatologists in the audience expressed amazement at the striking cultural difference between the United States and Japan as reflected in the greater than 95% attendance rate for routine annual health checkups in Dr. Saeki's study.
"In my country it seems like nobody comes in," commented an American physician.
As with an earlier Australian study, prevalence was higher in women and declinedwith age. DR. SAEKI