Early and late onset childhood eczema: Role of preconceptional, pre-natal and post-natal environmental exposures

Abstract

BackgroundDespite mounting evidence linking indoor and outdoor environments to eczema, the role of indoor and outdoor environmental pollutant(s) exposure during critical time window(s) on eczema remains unknown. ObjectiveTo investigate the correlations between childhood eczema and itchy rashes and exposure to outdoor air pollution and the home environment. MethodsA combined cross-sectional and retrospective cohort study of 8689 kindergarten students was conducted. We collected information about each child's health outcomes and home environment, as well as calculated individual exposure to air pollutants. Multiple logistic regression models were used to investigate the links between indoor and outdoor environments and childhood eczema and itchy rashes. ResultsChildhood ever doctor-diagnosed eczema (DDE) was linked to NO2, CO, PM2.5, PM2.5-10 and PM10 exposure during the preconceptional, pregnant, and postnatal periods, with ORs (95 % CI) ranging from 1.06 (1.00–1.13) to 1.21 (1.08–1.37). Ever doctor-diagnosed itchy rash (DDIR) was associated with SO2, CO, PM2.5, PM2.5-10 and PM10 exposure during preconceptional and postnatal periods, with ORs (95 % CI) ranging from 1.11 (1.02–1.20) to 1.31 (1.13–1.52). Preconceptional outdoor air pollution was associated with a higher risk of ever, early, and late DDE and DDIR. Indoor smoke, renovation, and dampness were all associated with DDE and DDIR. Postnatal exposure to plants has been linked to both ever and early DDE. There was no link between indoor environments and late DDE. Furthermore, pregnancy has been identified as a critical indoor exposure time window for DDE and DDIR. ConclusionsEarly-life exposure to outdoor air pollutants and indoor environments, particularly before birth, played important roles in childhood eczema.