September 07, 2016
1 min read

Antibiotics in early life linked with increased risk for allergy

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Exposure to antibiotics in early life is associated with an increased later risk for both eczema and hay fever, according to data presented at the 2016 European Respiratory Society International Congress, in London.

In a press release, Fariba Ahmadizar, PharmD, of Utrecht University, in the Netherlands, and colleagues, suggest that the mechanism behind the association is the immunomodulatory effect of the antibiotics, and the disruption of the microorganisms in the gut caused by antibiotics, which can lead to reduced immune responses.

To examine the association between allergies and antibiotic exposure in early life, the researchers reviewed observational studies published from January 1966 through Nov. 11, 2015, gathered through the PubMed and Web of Science databases. Included studies assessed the association between antibiotic exposure within the first 2 years of life and the risk for eczema or hay fever later in life.

The researchers identified 22 studies, including 394,517 patients, assessing the risk for eczema, and 22 studies, including 256,609 patients, determining the risk for hay fever. Of those, 12 studies, including 64,638, analyzed the risk for both conditions. Overall pooled estimates of odds ratios (OR) were obtained by using fixed or random-effects models.

According to the researchers, the summary ORs for eczema risk were 1.24 (95% CI, 1.09-1.41; I2 = 60%) in the meta-analysis of the cohort studies. In the cross sectional studies, the OR for eczema risk was 1.41 (95% CI, 1.33-1.49; I2 = 0%), and in the case control studies the OR was 1.15 (95% CI, 1.01-1.42; I2 = 79.5%). The summary ORs for the risk for hay fever were 1.18 (95% CI, 1.01-1.37; I2 = 74.3%) in the cohort studies, 1.56 (95% CI, 1.29-1.9; I2 = 63.6%) in the cross sectional studies, and 1.14 (95% CI, 1.04-1.26; I2 = 64.8%) in the case control studies. – by Jason Laday


Ahmadizar F, et al. Early life antibiotic exposure is associated with an increased risk of allergy.  Presented at: ERS International Congress; Sept. 3-7; London.