Purpose. There has been much interest in the effect of various microbial exposures early in life on the subsequent development of atopic disease. This study aimed to examine the effects of several exposure types on atopic sensitization.
Study Population. This was a cross-sectional study of 4111 Dutch schoolchildren aged 8 to 13 years.
Methods. A questionnaire evaluating day care attendance before age 4, cats or dogs in the home before age 2, siblings, history of doctor-treated airway disease before age 2, and current respiratory status was used. Atopic status was tested by either skin-prick testing or antigen-specific immunoglobulin E levels to multiple common antigens.
Results. Complete data were available for 1555 of the participants. Atopic sensitization was less frequent in children who attended day care (adjusted odds ratio: 0.74; 95% CI: 0.56–0.99) or had a pet in the home (adjusted odds ratio: 0.78; 95% CI: 0.61–0.99). There was no statistically significant association between the presence of siblings or the occurrence of doctor-treated airway disease and atopy.
Conclusion. Day care attendance and having a pet in the home may provide a protective effect against atopic sensitization.
Reviewer Comments. This study attempts to help clarify factors that may be associated with the primary development of atopy, which has been an area of great interest, especially given the rising prevalence of allergic disease. The results are consistent with many other studies indicating that microbial exposure early in life may have a preventive effect. Additional studies, including prospective cohorts, are being performed to define these associations more clearly. With luck, one day we will be able to use this information to design effective preventive strategies.
- Copyright © 2006 by the American Academy of Pediatrics