Allergy to insect sting. III. Allergenic cross-reactivity among the vespid venoms.

Recent reports have indicated that venoms may be more beneficial than whole body extracts for the diagnosis and treatment of Hymenoptera sensitive patients. These studies were undertaken to determine the cross-reactivity among the vespid venoms. Eighteen patients who were anaphylactically sensitive to vespid venoms were studied using in vitro leukocyte histamine release. The results (venom concentration for 50% histamine release) were analyzed by linear regression analysis; there was no allergenic cross-reactivity between any of the venoms, except for a modest association between yellow hornet and white hornet venom. In spite of this result 13 of the 18 patients studied were sensitive to three or four of the venoms tested. There is no clear explanation for this observation, but it suggests the existence of multiple major allergens in the vespid venoms, some of which are cross-reactive. Since immunotherapy with inappropriate proteins may lead to the development of IgE and the possibility of clinical sensitivity and since the majority of patients were not sensitive to all venom preparations, we suggest that appropriate diagnostic studies be carried out before the institution of therapy.