Four phenotypes of atopic dermatitis in Japanese children: A general population birth cohort study

Dear Editor, Atopic dermatitis (AD) is a common skin disease characterized by a chronic eczematous skin disorder with pruritus. A nationwide birth cohort study in Japan found that 15.7% of pregnant women had a past history of AD diagnosis. A European cohort study identified the allergic features of AD and found that the presentations of wheezing and rhinitis varied in the allergic march. Capturing phenotypes identified by different trajectories could lead to personalized precision medicine. Although our research team previously reported five phenotypes of wheezing in Japanese children in a prospective birth cohort study, the AD phenotypes in Japanese children have never been determined. The aim of this study was therefore to identify the AD phenotypes and to assess the associated risk factors in Japanese children. This general prospective birth cohort study, called the Tokyo Children's Health, Illness and Development study (T-CHILD study), was conducted at the National Center for Child Health and Development (NCCHD).