Systematic review of the relationship between early introduction of solid foods to infants and the development of allergic disease.

OBJECTIVE To assess the evidence that early solid feeding (before age 4 months) increases the risk of allergic disease. DATA SOURCES MEDLINE, the Cochrane Library, and the Drugs and Pharmacology section of EMBASE with key words "infant," "food," and "allergy." STUDY SELECTION We found 2719 article citations and reviewed references of relevant articles. We critically evaluated the methods and results of articles that met inclusion criteria. We identified 13 studies that met inclusion criteria. There was only 1 controlled trial. DATA EXTRACTION Allergic disease. DATA SYNTHESIS Five studies found a positive association between early solid feeding and eczema, with a persistence of the association for 10 years in 1 study. Four studies found no association. One study found an association between early solid feeding and pollen allergy. We found no strong evidence to support the association between early solid feeding and the development of persistent asthma, persistent food allergy, allergic rhinitis, or animal dander allergy. CONCLUSIONS Systematic review of available evidence suggests that early solid feeding may increase the risk of eczema. However, there are little data supporting an association between early solid feeding and other allergic conditions. Since many studies had problematic methods, additional controlled trials are needed to help guide physicians as they advise parents about the allergic risks of early introduction of solids.