Food Hypersensitivity: Gastrointestinal disturbances, skin eruptions, or shock due to allergic reactions to allergens in food.Milk Hypersensitivity: Allergic reaction to milk (usually cow's milk) or milk products. MILK HYPERSENSITIVITY should be differentiated from LACTOSE INTOLERANCE, an intolerance to milk as a result of congenital deficiency of lactase.Immunoglobulin E: An immunoglobulin associated with MAST CELLS. Overexpression has been associated with allergic hypersensitivity (HYPERSENSITIVITY, IMMEDIATE).Hypersensitivity, Delayed: An increased reactivity to specific antigens mediated not by antibodies but by cells.Drug Hypersensitivity: Immunologically mediated adverse reactions to medicinal substances used legally or illegally.Food: Any substances taken in by the body that provide nourishment.