IGHE and Allergy: Research was carried out through MEDLINE via PubMed (http://www.ncbi.nlm.nih.gov/pubmed/), Embase, CINAHL, and Cochrane Library, based on the combinations of two or more of the following keywords: (Food allergy) AND (nutrition OR diet OR prevention OR avoidance diet OR early introduction) AND (milk OR egg OR peanut OR fish OR cereal OR tree nut) AND (tolerance OR immunotherapy) AND (IgE-mediated OR non-IgE-mediated) AND (children OR pediatrics).