Medical Conditions - Hypersensitivity Reaction

An exaggerated body's immune response to certain allergens causes hypersensitivity reactions. Potential allergens are pollens, bee venom, drugs, food items, etc. Four types of hypersensitivity reactions are anaphylaxis, cytotoxic, immune complex, and delayed reactions. Examples include allergic rhinitis, conjunctivitis, drug-induced hemolytic anemia, contact dermatitis, food allergy, hay fever, angioedema, atopic eczema, erythema, etc.