Severe stinging insect allergy affects over 9.5 million Americans including 3 percent of adults and up to 1 percent of children. There are 40 to 100 deaths in the U.S. each year, and that number has not changed in the past 30 years.

An adult who has experienced anaphylaxis with a sting has a 60 to 70 percent chance of having a similar or more severe reaction with the next. Fortunately, venom immunotherapy is 95 to 98 percent effective in preventing such reactions and can be lifesaving therapy.

Stinging insects belong to the order Hymenoptera, which include the Apidae family (honeybee, sweatbee and bumblebee) and the Vespidae family (yellow jackets, yellow hornets, white-faced hornets, and paper wasps).

Yellow jackets are the most frequent culprits in North America. Yellow jackets are scavengers, and seek food at picnics and in trashcans, orchards and dumpsters. They are highly aggressive and sting for no apparent reason, especially in autumn while competing for limited food supplies. They tend to nest in the ground, or in cracks in buildings or landscaping materials. Hornets are aerial nesters, often building in trees and bushes, and are sensitive to vibration and noise, such as lawn mowers.

Paper wasps are found in the eaves or windows of houses and around decks. They have a narrow waist but can be a multitude of colors, including black, brown, red or striped. The Mediterranean wasp is now in the U.S., and has black and yellow stripes, which commonly lead to it being mistaken for a yellow jacket.

Honeybees are usually docile except for the Africanized hybrids, which tend to swarm and be more aggressive. The venom, however, is the same. Most honeybee stings are seen in beekeepers or people who play outdoors without shoes or garden without gloves.

Insect reactions usually can be treated with ice, pain control and antihistamine, but early use of steroids within the first hours after a sting can be helpful, especially to stings around the face, head and neck. Infection is unusual in sting reactions, except with yellow jackets.

Large local reaction swelling that develops after 24 to 48 hours usually is related to the allergic process and not infection.

Learn about testing and treatments for insect allergies.