IGHE and food allergy: FA can be categorized in (a) IgE-mediated allergic reactions, characterized by an acute onset of symptoms, usually within a few minutes or a few hours after exposure to food antigen; (b) non-IgE mediated reactions, where there is a delayed onset of symptoms, mainly gastrointestinal ones; and (c) mixed IgE and non-IgE mediated food allergy.