BANV Membership

REFLECTIONS ON INSECT STINGS by Dr. Barry Thompson


Notes from his presentation at BANV meeting May 2004

Solitary and eusocial insects may sting. Stings are more likely from wasps and yellow jackets than honeybees. A very small percentage of stings cause an allergic reaction. Many think or may be told that they are allergic when what they experience is the common reaction to the sting. Very few people can identify the insect. Everything is “a bee.” Documentation is lacking of true allergic responses or offending insects.

Levels of reaction include (1) Local reaction; (2) Large/expanded local reaction; (3) Toxic envenomation; and (4) Anaphylactic shock. The local reaction consists of a wheal and flare. The wheal is the swelling at the site of the bite, and the flare is the surrounding redness. This is usually a dime sized area in total. Pain is localized to the area of the sting. Itching at the sting site usually starts after several hours and may persist a day or two.

The expanded local reaction may look alarming because of the size of the affected area, but it is not an allergic reaction. The sting may affect a much larger area of contiguous tissue, so the wheal and flare are much larger and may cause distortion of tissue (like the face or hand). There may be urticaria (hives) in the affected area, but there is no general distribution of urticaria. (If the hives are accompanied by swelling and blotchiness over all the body, this may be of concern. Medical consultation should be sought promptly as this may be the first stage of hypersensitivity.)

Toxic envenomation can occur when the sheer number of stings introduces enough venom to have a whole body effect. Usually, the fact that one has been stung many times is obvious, and medical attention will and should be sought. A fatal dose for a healthy person may be as much as 800 to 1000 stings.

A true allergic reaction or anaphylaxis has a very rapid onset and progresses very rapidly. Anaphylaxis means the body is not protecting itself. The word comes from “ana” meaning ‘not’ and “phylaxis” meaning ‘guarding or protecting’. In a normal response of the body to foreign protein (such as contained in venom), antibodies (IgG) are produced. Upon subsequent exposure to the same protein, these antibodies "protect" the body. In the instance of true allergy or hypersensitivity, E group antibodies (IgE) are produced. Exactly what induces this response (rather than the usual IgG production) is yet to be completely understood. Individuals, including beekeepers, may develop allergy or hypersensitivity unexpectedly after repeated exposure to bee venom. When these IgE antibodies, attached to mast cell surfaces, encounter the foreign protein, excessive amounts of histamine may be released. This release of histamine (along with other substances) produces a variety of responses in the human body that may lead to respiratory distress or cardiovascular collapse (shock) and death.

If the patient stops breathing, CPR may be necessary. The only thing to interrupt the allergic response is the injection of epinephrine (adrenaline). Two commonly available commercial kits containing injectable epinephrine are the AnaKitTM and EpiPenTM. Bronchodilators may be helpful in relieving airway compromise, but one may not be available. Oral antihistamines may have some effect, but administration by mouth takes too long to be effective.

A shot of epinephrine must be given at the first sign of a true allergic reaction, and emergency medical care should be sought immediately. Even after the epi dose, 2-4 hours later there can be a 2nd response in the body. It is virtually impossible to injure a person when injecting epinephrine unless there is an underlying medical problem (such as an individual with high blood pressure or an older person who is taking beta blockers.) As epinephrine may increase blood pressure, there is a possible increase in the risk of stroke. There is a small risk to the recipient; however, dying from anaphylaxis is worse. There is a 10% crossover between allergic reactions to honeybees and paper wasps and yellow jackets.

If you are truly allergic, you can go through desensitization. This involves skin testing and then administering small, controlled amounts of bee venom over a period of time.