Stings by bees, wasps, and hornets are common throughout the United States. Some ants also sting. The average person can safely tolerate 10 stings for each pound of body weight. This means that the average adult could withstand more than 1,000 stings, whereas 500 stings could kill a child. However, one sting can cause death from an anaphylactic reaction (a life-threatening allergic reaction in which blood pressure falls and the airway closes—see Allergic Reactions and Other Hypersensitivity Disorders: Anaphylactic Reactions) in a person who is allergic to such stings. In the United States, 3 or 4 times more people die from bee stings than from snakebites. A more aggressive type of honeybee, called the Africanized killer bee, has reached the southern and some southwestern states from South America. By attacking their victim in swarms, these bees cause a more severe reaction than do other bees.
In the South, particularly in the Gulf region, fire ants sting up to 40% of the people who live in infested areas each year, causing at least 30 deaths.
Bee, wasp, and hornet stings cause immediate pain and a red, swollen, sometimes itchy area about ½ inch (about 1 centimeter) across. In some people, the area swells to a diameter of 2 inches (5 centimeters) or more over the next 2 or 3 days. This swelling is sometimes mistaken for infection, which is unusual after bee stings. Allergic reactions may cause rash, itching all over, wheezing, trouble breathing, and shock.
The fire ant sting usually causes immediate pain and a red, swollen area, which disappears within 45 minutes. A blister then forms, rupturing in 2 to 3 days, and the area often becomes infected. In some cases, a red, swollen, itchy patch develops instead of a blister. Isolated nerves may become inflamed, and seizures may occur.
A bee may leave its stinger in the skin. The stinger should be removed as quickly as possible by scraping with a thin dull edge (for example, the edge of a credit card or a thin table knife). An ice cube placed over the sting reduces the pain. A cream or ointment containing an antihistamine, an anesthetic, a corticosteroid, or a combination of them is often useful. Severe allergic reactions are treated in the hospital with epinephrine, intravenous fluids, and other drugs.
People who are allergic to stings should always carry a preloaded syringe of epinephrine (available by prescription), which helps reverse anaphylactic or allergic reactions. Other stings are treated similarly to bee stings. People who have a history of anaphylactic reactions or a known allergy to insect bites should wear identification, such as a medical alert bracelet.
People who have had a severe allergic reaction to a bee sting sometimes undergo desensitization (allergen immunotherapy—see Allergic Reactions and Other Hypersensitivity Disorders: Allergen immunotherapy), which may help prevent future allergic reactions.
Last full review/revision February 2009 by Robert A. Barish, MD, MBA