Association Between the Age of Solid Food Introduction and Eczema: A Systematic Review and a Meta-analysis

Abstract

To review all available literature to determine if the timing of solid food introduction influences the risk of atopic eczema. Cow’s milk was purposely excluded in this review because it is not given as a solid food.Children enrolled in 11 cohort studies, 2 case controls, 1 cross-sectional study, and 2 randomized controlled trials were included.PubMed and Embase databases were searched using the key words solid food, complementary and allergenic food introduction, and eczema, with the final literature search performed on February 18, 2017. Two authors independently assessed all applicable English-language human studies and performed data extraction. Cohort studies, case-controlled studies, cross-sectional studies, and randomized controlled trials containing original data were included in this review.A total of 1414 articles were initially identified; after removal of duplicates, 1092 articles underwent title and abstract screening, with 987 articles being excluded. The remaining 105 articles underwent full text review, and 89 articles were excluded. A total of 17 articles met the inclusion criteria: 11 were cohort studies (1 cohort study generated 2 publications), 2 were case controls, 1 was a cross-sectional study, and 2 were randomized controlled trials. In the 2 randomized controlled trials, researchers examined early egg introduction; in 1 of these studies, researchers showed that early egg introduction (between 4 and 6 months) may reduce the risk of atopic eczema, whereas researchers in the other trial failed to demonstrate this response. Because of heterogeneity between the studies, a limited meta-analysis was performed; this did not show an association between the age of solid food introduction and risk of eczema.No strong evidence was found that early solid food introduction was associated with less risk of atopic eczema.Every day, parents ask health care providers, when should my infant start solid foods? How early is early? Can this help prevent eczema? The takeaway from this study is that early solid food introduction has little bearing on an infant’s risk of eczema development. On the basis of recommendations from many national and international health organizations, solid food introduction should occur around 6 months of age and not before 4 months of age.