Group

Hypersensitivity is an exaggerated or inappropriate immune response to a substance (called an allergen or antigen) that is normally harmless or only mildly harmful. These reactions can damage tissues and range from mild symptoms to life-threatening emergencies.

Common causes

Hypersensitivity reactions may be triggered by:

• Foods (e.g., peanuts, shellfish)

• Medications (e.g., certain antibiotics)

• Insect stings