Development of Insect Sting Allergy

Stinging insect allergy is a relatively common medical problem, responsible for an estimated 40 fatalities per year in the USA and considerable anxiety and lifestyle modification. There are no criteria to identify people at risk of initial venom anaphylaxis. Reactions may occur at any age and are unrelated to the time interval of prior venom exposure. There is an approximate 60% re-sting reaction rate in people who have had sting anaphylaxis and have positive venom skin tests. Re-sting reactions are more likely to occur in adults than in children and in people who have had more severe anaphylactic symptoms. Positive venom intradermal skin tests confirm the diagnosis of potential stinging insect allergy in people who have had sting reactions. Venom immunotherapy provides almost 100% protection from further sting reactions. It is recommended for all people who have had venom anaphylaxis and have positive skin tests, except for children who have dermal reactions only. Details of venom dosing are well established. The adequate duration of venom immunotherapy is still an unresolved issue. Conversion to a negative skin test appears to be an absolute criterion to discontinue treatment. In the presence of a persistent positive skin test, 3–5 years of immunotherapy is generally sufficient. People who have had severe reactions, such as loss of consciousenss, may require indefinite therapy.