Background: Evidence on the association between antibiotics and the risk of food allergies is limited. We explored the associations between mother’s and offspring’s use of antibiotics and the risk of cow’s milk allergy in infancy.
Methods: We used a national registry to identify all children who were born in 1996–2004 in Finland and diagnosed with cow’s milk allergy after 1 month of age by November 2005 (n = 15,672). For each case, we selected one control matched for birth date, sex, and hospital district. Information on antibiotic purchases and putative confounders was obtained from registries. The associations were analyzed using conditional logistic regression.
Results: Maternal use of antibiotics before and during pregnancy was associated with an increased risk of cow’s milk allergy in the offspring (odds ratio = 1.26 [95% confidence interval = 1.20–1.33] and 1.21 [1.14–1.28], respectively, adjusting for putative confounders). The risk of cow’s milk allergy increased with increasing number of child’s antibiotics used from birth to diagnosis (test for trend P < 0.001).
Conclusions: Both maternal and child’s use of antibiotics were associated with an increased risk of cow’s milk allergy. Future studies are needed to confirm these novel findings and to explore the potential biologic mechanisms behind the association.
From the aDepartment of Lifestyle and Participation, National Institute for Health and Welfare, Helsinki, Finland; bTampere School of Public Health, University of Tampere, Tampere, Finland; cDepartment of Health, Functional Capacity and Welfare, National Institute for Health and Welfare, Helsinki, Finland; dResearch Department, Social Insurance Institution, Turku, Finland; ePediatric Research Centre, Tampere University Hospital and University of Tampere, Finland; fDepartment of Information, National Institute for Health and Welfare, Helsinki, Finland; gNordic School of Public Health, Gothenburg, Sweden; and hResearch Unit, Tampere University Hospital, Tampere, Finland.
Submitted 10 June 2011; accepted 21 November 2012.
Supported by Juho Vainio Foundation, Yrjö Jahnsson Foundation, and fellowship in Doctoral School of Public Health with funding from Ministry of Education and Culture, Finland.
Correspondence: Johanna Metsälä, Department of Lifestyle and Participation/Nutrition Unit, National Institution for Health and Welfare, P.O. Box 30, FI-00271 Helsinki, Finland. E-mail: firstname.lastname@example.org.