An allergic reaction occurs when the immune system overreacts to an allergen in the venom of a stinging or biting insect. Symptoms include itching, rash, hives, joint swelling, inflammation at or around the site of the sting or bite, difficulty breathing, or a severe reaction called anaphylaxis.

Treatment for insect sting allergies depends on how severe the reaction is. Mild local reactions can often be treated with cold packs and medications for pain, swelling, and itching. An epinephrine shot can treat more serious reactions. A severe reaction (anaphylaxis) is potentially life-threatening and requires emergency care.