Asthma risk higher in children given antibiotics in their first year of life

Kids exposed to antibiotics in the first year of life had double the risk of developing early-onset childhood asthma, according to a study published online in Annals of Allergy, Asthma & Immunology.

Mei-Sing Ong of the Australian Institute for Health Innovation, University of New South Wales, Sydney, Australia, and Children's Hospital Informatics Program at Harvard-MIT Health Sciences and Technology, Boston Children's Hospital, Boston, and colleagues conducted a retrospective population-based study of children enrolled in a nationwide employer-provided health insurance plan from 1999 through 2006 in the United States (n=1,604,580).

The study population consists of all children (n=62,576) continuously enrolled from birth through to at least aged 5 years. Comprehensive prescription and diagnosis data were extracted from claims.

“We assessed the relationship between antibiotic exposure in the first year of life and subsequent development of 3 asthma phenotypes: transient wheezing [began and resolved before aged 3 years], late-onset asthma [began after aged 3 years], and persistent asthma [began before aged 3 years and persisted through to aged 4 to 7 years],” said one of the study's authors Kenneth D. Mandl, MD, MPH, professor, at Harvard Medical School.

“We adjusted our results for gender, geographic region, and exposures to respiratory infections in infancy,” he said.

“This effect has a clear dose response. In half of these children, early asthma was transient and resolved by the age of 3,” said Dr Mandl. “In the remaining children, early asthma persisted after the age of 3 through to at least 7 years of age.”

“The overuse of antibiotics can adversely affect the immune development of children,” said Dr Mandl. “Clinicians should be cautioned against unnecessary use of antibiotics, especially in low-risk children.”

Increasing evidence supports the link between excessive antibiotic use and immune-mediated diseases, not just asthma, but also inflammatory bowel disease, according to Dr Mandl. “Clinicians should be encouraged to prescribe antibiotics only when necessary,” he concluded.