When a person is stung by a bee, wasp, hornet, yellow jacket or fire ants, the insect injects venom into its victim. This venom can cause severe life threatening reactions in certain people who are allergic to it. In a typically normal reaction the sting site will be painful, reddened, may swell and itch, but this will last only few hours. Enlarged local reactions might be seen with a painful swelling of several inches surrounding the area of the sting. This reaction might last for days.

In a severe allergic reaction the person might feel dizzy, nauseated and weak. Stomach cramps and diarrhea may occur. Generalized hives and itching, wheezing and difficulty breathing, and potentially an anaphylactic reaction with a sudden drop in blood pressure, loss of consciousness which may lead to death if no immediate medical care is provided. There is clear evidence that venom immunotherapy in the majority of patients is protective for any future life threatening reactions. Patients with known allergic sensitivities to insect venom should be evaluated by the allergist and placed on protective desensitization therapy.