Early Introduction of Egg and the Development of Egg Allergy in Children: A Systematic Review and Meta-analysis

Abstract

To systematically review the existing literature regarding the effect of early introduction of egg on the development of egg allergy.Data were included from a total of 3032 infants from the following countries: Australia, Germany, Japan, and the United Kingdom.Literature searches were conducted in Medline, Embase, and CENTRAL, and trial protocols were searched in Meta Register and OpenGREY. Only randomized controlled trials comparing early (3 to 6 months) egg introduction with no early introduction were included.Six randomized controlled trials met criteria for data extraction. A low to moderate level of evidence showed a benefit of early egg introduction (risk ratio: 0.60; 95% confidence interval: 0.44–0.82; P = .002). Consumption of <4000 mg per week of egg protein had a greater preventive effect compared with a higher dose.In this systematic review and meta-analysis, researchers showed an association between the early introduction of egg and a lower risk of egg allergy.This study supports the evolving body of evidence that foods should not be avoided during infancy because early introduction in high-risk infants (either having eczema or a family history of atopy) may be protective for allergy. Of the studies analyzed, only 1 demonstrated clear benefit. The researchers in this study used a much lower weekly dose of egg protein compared with the other studies. Also, of note, this study used heated whole egg powder, whereas most of the studies used pasteurized raw egg powder. Additional studies are needed with a true-to-life approach in which egg would be prepared by various means of cooking.