Objectives: This study examined the associations of history of ear infections in infancy with doctor-diagnosed asthma in a large sample of Mexican American children.
Methods: In this population-based cross-sectional study, parents of 2023 children completed a questionnaire that collected data on doctor-diagnosed asthma, doctor-diagnosed ear infections, as well as antibiotics use in infancy, and other potential confounding variables.
Results: Children with a history of ear infections in infancy were more likely to have asthma compared with those who had no history of ear infections in infancy; the adjusted odds ratios (ORs) were 2.52 (95% confidence interval [CI]: 1.35-4.69) and 1.27 (95% CI: 0.79-2.04) in children who had >or=3 and 1-2 (versus none) ear infections in infancy, respectively, p for trend = .0074. These associations were independent of antibiotics use, acetaminophen consumption, and history of various infections (other than ear infections) in the first year of life. In stratified analyses, the increased risk of asthma in children with recurrent ear infections in infancy persisted among children whose parents reported no lifetime history of rhinitis but not in children who had a history of rhinitis.
Conclusions: This study demonstrated significant associations of asthma with history of ear infections in infancy, with a significant dose-response effect of repeated ear infections on the odds of asthma. These findings add to the growing body of literature linking early childhood infections with the risk of asthma and highlight the need for more research to identify the mechanisms through which ear infections may be associated with asthma.