Seasonal attack patterns in childhood atopic dermatitis are related to different environmental factors

BACKGROUND AND AIM: Atopic dermatitis (AD) is a prevalent childhood condition involving many people. The attack pattern has been quite diverse. Few studies have classified AD children into subgroups according to seasonal attack pattern. This study explores the methods to group AD children into seasonal attack patterns, and examines hereditary and environmental factors on each subgroup in children with AD. METHODS: In Taiwanese children from one elementary and one middle schools in each of the 22 cities/counties, allergic status, hereditary and living environmental factors were surveyed in 2016, as well as air pollutants by air monitoring stations. Among those with current AD, principal component analyses on weighted moving average of monthly attack score was applied to categorize AD attack subtypes. Generalized Estimating Equation was used to study the effects of environmental exposure on each AD attack subgroups. RESULTS: A total of 11,585 children were surveyed, and 17.6% of children reportedly had AD attack in the past 1 year. Among them, four attack patterns were identified: spring, summer/fall, winter and perennial. Parental atopic diseases and higher education, and molds in residence are important factors for AD. Among seasonal attack patterns, lower temperature, higher humidity, and PM2.5 were related to spring-attack; higher temperature to summer-fall-attack; lower humidity to winter-attack; and traffic-related air pollutants to perennial-attack AD. CONCLUSIONS: Distinguished attack patterns are identified in children with current AD. Depending on individual attack subtypes, environmental factors can be different. KEYWORDS seasonal attack pattern; atopic dermatitis; environmental factors; GEE