Hypersensitivity states the body mounts against foreign antigens that are harmless to most people at similar doses. Food allergies are typically Type I reactions, in which immunoglobulin E triggers mast cells to release histamine — producing hives, vomiting, respiratory distress and, at the extreme, anaphylaxis within minutes. Most foods have provoked reactions in someone, but the common adult triggers are peanut, tree nuts, fish, shellfish, milk, egg, soy, wheat and sesame. Prevalence has risen in many countries, driving labelling laws, allergen management in factories and research into desensitisation therapies.