A Systematic Review

TAKE-HOME MESSAGE

• In a systematic review and meta-analysis of 20 studies, postnatal exposure to antibiotics during the first year of life was associated with an increased risk for eczema (odds ratio, 1.41), with an increased risk of 7% for each additional antibiotic course received.
• These data indicate that antibiotic use early in life may play a role in the development of eczema, and pediatricians should be aware of this association when prescribing antibiotics. The “hygiene hypothesis” is a related concept, which suggests that development of normal immune mechanisms and tolerance require exposure to certain bacteria that may be eliminated by antibiotics. This article could be discussed with parents and our pediatric colleagues.

Commentary By:  Sarah L Chamlin, MD

The hygiene hypothesis is commonly suggested as an explanation for the increasing prevalence of atopic dermatitis. Of note, the pathogenesis of atopic dermatitis is multifactorial and likely includes this hypothesis and other factors that alter immunity early in life and predispose some children. These authors investigated postnatal and antenatal antibiotic exposure as a contributing factor to atopic dermatitis development. While conflicting data exist on this topic, this meta-analysis and systematic review supports that antibiotic exposure in the first year of life is more common in children with atopic dermatitis, and that this association may be dose-dependent. A potential explanation offered is disrupted gut microflora that alters immunity. While this seems feasible, data in many of these studies are confounded, and more investigation is warranted.

ABSTRACT

A number of studies have suggested that early life exposure to antibiotics can lead to an increased risk of developing eczema. This systematic review and meta-analysis of observational studies, involving children or young adults aged 0-25 years, assessed the impact of antibiotic exposure either in utero or during the first 12 months of life on subsequent eczema risk. Twenty studies examined the association between prenatal and/or postnatal exposure to antibiotics and development of eczema. The pooled odds ratio (OR) for the 17 studies examining postnatal antibiotic exposure was 1·41 [95% confidence interval (CI) 1·30-1·53]. The pooled OR for the 10 longitudinal studies was 1·40 (95% CI 1·19-1·64), compared with a pooled OR of 1·43 (95% CI 1·36-1·51) for the seven cross-sectional studies. There was a significant dose-response association, suggesting a 7% increase in the risk of eczema for each additional antibiotic course received during the first year of life [pooled OR 1·07 (95% CI 1·02-1·11)]. Finally, the pooled OR for the four studies relating to antenatal exposure was 1·30 (95% CI 0·86-1·95). We conclude that exposure to antibiotics in the first year of life, but not prenatally, is more common in children with eczema.

Practice Update Webpage:  http://www.practiceupdate.com/journalscan/6663

Journal Abstract:  http://onlinelibrary.wiley.com/doi/10.1111/bjd.12476/abstract;jsessionid=D21D1D605BD70BBB711AD0C7AA2FC2F0.f01t03