Coeliac disease and asthma association in children: the role of antibiotic consumption.

The relationship between coeliac disease and asthma has been scarcely investigated. Infant antibiotic exposure has been linked to both diseases. We evaluated the association between childhood coeliac disease and asthma and the role of antibiotics in the first year of life. We followed a cohort of children born in 1995-2011 in the Friuli-Venezia Giulia region (Italy). Prescriptions for antibiotics in the first year of life and subsequent treated asthma were retrieved from drug prescription records; coeliac disease incident cases were identified from pathology reports, hospital discharges and exemption from prescription charges for clinical tests. We estimated incidence rate ratios (IRRs) using multivariate Poisson regression models. Among the 143,144 children, we identified 717 coeliac children and 34,969 asthmatics. Children with asthma were at increased risk of coeliac disease (IRR 1.46, 95% CI 1.25-1.67). Restricting the analysis to asthma that occurred before the diagnosis of coeliac disease, the excess risk disappeared, except for coeliac disease diagnosed after 5 years of age (IRR 1.37, 95% CI 1.09-1.71). Antibiotics were not a confounding factor in these associations. Childhood treated asthma and coeliac disease are significantly associated. This association is not confounded by antibiotic exposure in the first year of life and may be explained by other shared risk factors.