The influence of bedroom environment on sensitization and allergic symptoms in schoolchildren.

BACKGROUND Bedroom conditions have been associated with an increased risk of allergy. OBJECTIVE The aim of this study was to evaluate the relationship between sleeping environment and sensitization and allergic symptoms in schoolchildren. METHODS A cross-sectional study, the Aalst Allergy Study, was performed in an unbiased community population of 2021 Belgian schoolchildren, aged 3.4 to 14.8 years. Skin prick testing was performed with the most common aeroallergens and bedroom conditions (presence of stuffed toys, type of flooring, and bedding material) were documented through a parental questionnaire. RESULTS The presence of stuffed toys in the bedroom was associated with a lower prevalence of overall sensitization and a lower prevalence of conjunctivitis and allergic respiratory symptoms. That effect was almost exclusively present in children with a positive family history of atopy and was more pronounced as the number of stuffed toys increased. A significantly lower prevalence of overall sensitization, sensitization to house dust mite, and wheezing was documented in children with nonsynthetic bedding materials. That effect was exclusive to children with a positive family history of atopy. Type of flooring was not associated with sensitization or allergic symptoms. CONCLUSION Our data suggest that bedroom exposure to stuffed toys and nonsynthetic bedding materials may have a protective effect against sensitization and allergic symptoms in genetically predisposed children. Confirmation of these findings will require further prospective studies that include measurement of levels of mite allergens and endotoxins and assessment of the time, degree, and duration of the exposure.