Hymenoptera venom allergy: a geographic study.

RAST results for the five common venoms from 1,024 positive sera obtained from patients who experienced recent severe allergic reactions to insect stings were analyzed for nine different geographic areas of the United States. Substantial differences were found as a function of geography and insect distribution. The results suggest that multiple reactivity is most common in areas with the most variety of insects, that cross reactivity is not the only important cause of multiple reactivity and that sensitization by multiple stings is more common than suggested by patient histories.