Does early-life antibiotic use cause asthma?

Published Online: June 19, 2014

Asthma prevalence has doubled in developed countries over the last 30 years and the concurrent increase in children’s antibiotic use has led to speculation of a possible causal relationship. Retrospective studies focused on the hygiene hypothesis have shown correlations with early antibiotic use. These findings, however, may be due to reverse causation, or confounding by indication. Existing evidence is inconsistent, and there have been few prospective studies.

In a Letter to the Editor recently published in The Journal of Allergy & Clinical Immunology (JACI), Lapin and colleagues detail an investigation into the effects of antibiotic use in the first year of life with subsequent asthma diagnosis and respiratory symptoms in the third year of life within a high-risk urban cohort. They used prospective data on 300 mother-child pairs from the Peer Education in Pregnancy Study, a randomized education intervention examining the effect of educators working with pregnant women at risk for having children with asthma.

The researchers analyzed the association between early antibiotic use, which was determined at multiple points during the first year of life, and an asthma diagnosis by 3 years of age or respiratory symptoms within the year prior to the third year visit. Reason for antibiotic use was separated into respiratory infections versus non-respiratory infections. Mothers were followed and surveyed in each trimester of pregnancy and children were followed from 4 weeks of age through age 3 years allowing the researchers to control for pertinent temporal confounders.

The authors found a significant relationship between antibiotic use within the first year of life and incident asthma and wheezing in year three which has been identified consistently in retrospective studies. After separating out indication for antibiotic use, the significant relationship between asthma and respiratory symptoms held only for antibiotics used for respiratory reasons. No outcomes were associated with antibiotics used for non-respiratory reasons. The authors’ findings suggest the associations found between antibiotic use in young children and subsequent development of asthma and wheezing may be due to reverse causation or confounding by respiratory infections.

The Journal of Allergy and Clinical Immunology (JACI) is the official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.

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