Stable incidence of atopic dermatitis among children in Denmark during the 1990s

An increase in the prevalence of atopic dermatitis (AD) has been reported since the 1960s. The increase could be due to many factors including a genuine increase of incidence or duration of AD. We decided to study if the increasing trend persisted during the 1990s by comparing the cumulative incidence of AD in 1993 and 1998. Further, we studied the severity and management of AD among children. Two samples of children born in Denmark were drawn from the Danish Medical Birth Register. In the 1993 and 1998 studies a mailed questionnaire with identical questions concerning AD was sent out. In the 1998 follow-up study the questionnaire included a severity score and questions concerning management of AD. In the 1993 study the cumulative incidence of AD at age 7 was 18.9% and in 1998 it was 19.6%. There was no difference in the age-adjusted AD incidence in the 5-year observation period. In the 1998 study, 81% had mild to moderate AD, 90% had been seen by a doctor at least once, 36% had mainly been treated by a dermatologist, and 2% had been hospitalized. It should be kept in mind that we base most of our common knowledge of the disease on AD patients selected for management in dermatology clinics and departments.