A study of Atopic dermatitis in elementary school children in Hirosaki city, Aomori prefecture, Japan.

The purpose of this study was to investigate the relationship between residential environments and atopic dermatitis (AD). Subjects were 1378 elementary school children from 4 elementary schools in Hirosaki City, Aomori Prefecture located in die northeastern of Japan. Physical examinations, which adhered to the diagnostic criteria set by die Japanese Dermatological Association, were given by dermatological specialists in October 1994 (first series) and April 1995 (second series). Half of die children with AD showed symptoms in only one of two seasons, either the autumn or spring, so the drifting of symptoms of AD occurred largely by seasons. The data on residential environments was gathered by questionnaire. Multiple logistic regression analysis showed that more children who were diagnosed positive as AD twice (AD(+,+)), lived in damp and moldy homes than did children who were diagnosed negative as AD twice (AD(-,-)). Moreover AD(+,+) were more likely to live in homes built between 1984 and 1989 than did AD(-,-). In addition, most AD(+,+) children frequently lived in homes in which the bedrooms were vacuumed 3-5 times or more in a week. Then damp and moldy houses or houses built between 1984 and 1989 may be risk factors for the outbreak of AD.