Allergies occur when your immune system reacts to a foreign substance such as pollen, bee venom or pet dander, hair dye or a food that doesn’t cause a reaction in most people.
The severity of allergies varies from person to person and can range from minor irritation to anaphylaxis — a potentially life-threatening emergency. While most allergies can’t be cured, treatments can help relieve your allergy symptoms. Treatment includes avoidance, medications, and emergency epinephrine for severe reactions.