Mold exposure affects the development of atopic dermatitis in early life especially in infants with epithelial dysfunction

RATIONALE: Effect of mold exposure on development of atopic dermatitis (AD) is inconclusive. The reasons for the inconsistent results might be contributed to differences in exposure timing, individual’s skin barrier dysfunction, or genetic factors. The aim of this study was to identify the association between mold exposure and development of AD. Also, we elucidated whether skin barrier dysfunction affects the effect of mold exposure on AD development.

METHODS: In the Cohort for Childhood Origin of Asthma and Allergic Diseases, 470 infants were enrolled. Mold exposure was assessed using questionnaire. AD were assessed by pediatric allergists at ages 1 and 2. Trans-epidermal water loss (TEWL) were measured at age 1. The association between mold exposure and AD was assessed using Cox proportional hazards and logistic regression models.

RESULTS: Mold exposure during pregnancy increased the risk of AD (hazard ratio 1.49; 95% confidence intervals [CIs] 0.91-1.98) after adjustment for postnatal mold exposure. When infants were exposed to mold during fetal periods, hazard ratio for AD was increased as 2.43 (95% CI, 1.46-4.05) in infants with high levels of TEWL. Levels of total serum IgE levels at age 1 (P = 0.001) as well as log transformed IL-13/ IFN-γ from the cord blood (P = 0.005) were increased in infants exposed to mold during fetal life with higher levels of TEWL, compared to those without mold exposure and lower levels of TEWL.

CONCLUSIONS: Mold exposure during fetal life increases the risk of AD in early life, especially in infant with skin barrier dysfunction, through Th2 allergic inflammation.