343 Gene-environment Interactions on the Development of Atopic Dermatitis in Preschool Children: Mold is the Main Environmental Factor

BACKGROUND: Genetic factor and environmental exposure are recognized risk factors for atopic dermatitis (AD) in children. It is known that fungus is the representative environmental factor of AD. However, the relative and the overall contributions of fungal exposure remain unexplored. METHODS: During July to August 2010 population-based cross-sectional survey, we investigate 986 preschool children from 16 kindergartens of Seoul and Gyeonggi-do province in Korea using a modified International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. We investigated 5 mold exposure items (dampness stain, dampness damage, visible mold, mold odor, house repair) in this survey. Multivariate regression analysis was applied to determine impact of mold exposure as risk factor for AD. RESULTS: The prevalence of AD was as follows: lifetime symptoms, 28.0%; symptoms in the past 12 months, 28.7%; lifetime diagnosis by questionnaire, 35.1%; treatment in the past 12 months, 16.6%; current AD (which was defined as lifetime diagnosis by questionnaire together with symptoms in the past 12 months), 21.5%; and diagnosis by doctor's examination on the spot, 14.6%. A parental history of AD and mold exposure and environmental factors were independent risk factors for AD in preschool children. The coexistence of a parental history of AD and mold exposure together was synergistically related to AD prevalence. When children with a parental history of AD were exposed to mold (ex. mold odor), the risk for AD prevalence increased up to 7 times. (OR 6.956, 95% CI, 2.599-18.615) CONCLUSIONS: This investigation provides a high prevalence of AD and a close relationship with mold. High prevalence of AD was detected by the combined effect parental history of AD and mold exposure at infancy. These findings suggest that early avoidance from mold exposure is important to prevent the development of AD especially in the susceptible children.