Insect Bites Or Sting Allergies

Insect stings usually produce only local irritation and discomfort. However, for an unlucky few, about 1% of us injected with insect venom during a sting can have more serious consequences. Reactions can range from a large local reaction to death due to an allergy to the venom.

Some people have symptoms of an allergic reaction to insect bites and insect stings from mosquitoes, horse flies, or deer flies. Usually, they do not need any testing or treatment except antihistamines. It is very rare that someone has a severe allergic reaction with insect bites. However, we do see large local reactions to mosquito bites.

The more severe reactions are due to insect stings. There are five insects in this part of the country that can cause severe reactions including life-threatening anaphylaxis. The most common is the yellow jacket, and two other insects called hornets. These three belong to the same family. The honey bee belongs to a different family, and usually, when a patient is stung by a honey bee, it leaves a stinger. Wasp is the fifth insect, and there are some cross-reactions between the wasp, the yellow jacket and the hornet venoms. The most common reaction with these insects is a local reaction, and we do not recommend any medical treatment. One percent of these patients ultimately may develop severe allergic reactions, but the incidence is no different than the general population.

The second most common reaction is a large, local reaction. Usually, the swelling gets worse a few hours later. This is treated with antihistamines and occasionally oral steroids if the swelling is very large. In general, they do not need allergy testing nor desensitization. About 10% of these patients ultimately may develop a systemic reaction if they get stung again.

The third reaction, which is not common but is life threatening, is a systemic reaction with hives, itching all over the body, swelling of the throat, wheezing and hypotension. Adults are at a higher risk than children for fatal reactions. Children with skin reactions only (hives) are not at high risk and do not need testing or treatment; however, adults that have a systemic reaction and children that have systemic symptoms involving respiratory, gastrointestinal or cardiovascular system must be tested and need desensitization. Both children and adults in this category need to carry an epinephrine kit and know how and when to use it.