[A LONG PROSPECTIVE OBSERVATIONAL STUDY ON PREVALENCE OF ATOPIC DERMATITIS IN EARLY CHILDHOOD TO ADOLESCENCE]

There are few prospective observational studies on the prevalence of atopic dermatitis (AD) in children. We aimed to prospectively investigate the dynamics of change in the prevalence of AD from early childhood to adolescence.

We conducted a survey with a modified questionnaire to diagnose AD based on The International Study of Asthma and Allergies in Childhood questionnaire with 1230 13-year-old children who were born in the Minami ward, Yokohama City between May 2004 and June 2005 and had undergone physical examinations by dermatologists at 3 years of age. Among the 422 children who answered the questionnaire, 210 had undergone periodic physical examinations by dermatologists from 4 months to 3 years of age (Cohort 1), whereas 212 had undergone physical examinations only at 3 years of age (Cohort 2).

The prevalence of AD was 16.9% in 422 children at 13 years of age, with 22.9%, 16.6%, 20.0% and 18.3% prevalence at 4 months, 18 months, 3 years and 13 years of age, respectively, in children who were followed up long-term. The frequency of AD occurrence per year decreased after the age of 3 years; a history of AD at this age was significantly related to AD at 13 years of age (Fisher's exact test, p<0.001).

In conclusion, it was suggested that AD in 3-year-old children is one of the risk factors for the development of AD in 13-year-old children.