INSECT STING ANAPHYLAXIS

Abstract

Insect sting anaphylaxis is a relatively common problem, estimated to affect at least 0.4% of the population. The allergic reactions are mediated by IgE antibodies directed against constituents in honeybee, yellow jacket, hornet, and wasp venoms. In addition, anaphylaxis occurs following stings by nonwinged Hymenoptera, the fire ant, and harvester ant. The anaphylactic symptoms are typical of those occurring from any cause. The majority of reactions in children are mild and frequently dermal (hives, edema) only. The more severe reactions such as hypotension and loss of consciousness can occur at any age but are relatively more frequent in adults. It is estimated that 40 to 50 deaths per year occur in this country from insect sting anaphylaxis, with the likelihood that others are undiagnosed. The majority of severe reactions and deaths have occurred in patients unaware of potential allergy. After sting anaphylaxis, about 50% of unselected patients will continue to react to re-stings in the absence of venom immunotherapy. Children with dermal reactions only have a benign course and are unlikely to have recurrent reactions. Patients with more severe reactions are likely to have repeat anaphylaxis of similar severity. Patients with a history of insect sting anaphylaxis and positive venom skin tests should have epinephrine available for self-administration, and are candidates for subsequent venom immunotherapy.