Topics: Humoral Hypersensitivity, Cell mediated Hypersensitivity, Systemic Anaphylaxis, Mast Cell, Diffuse urticaria, Allergens, Localized Anaphylaxis, Immediate Hypersensitivity, Acute Allergic Response, Anaphylaxis, Anaphylactic Shock, angioedema, Genetic Predisposition, Eosinophils, Systemic anaphylaxis, Antibody-Mediated Cytotoxicity, Subacute Hypersensitivities, Hemolytic disease of newborn, Myastenia gravis, thrombocytopenic purpura, Immune Complex Disease, Serum Sickness, Systemic immune complex disease, rheumatoid arthritis, systemic lupus erythematosus, contact dermatitis, Delayed type hypersensitivity