Diagnosis and treatment of anaphylactic reactions to Hymenoptera stings in children.

Forty-four children (mean age 9.6 years) with a history of an allergic reaction(s) to an insect sting and with positive insect venom skin tests were studied. IgE antibodies (RAST) to honeybee phospholipase A and to yellow jacket venom were found in the sera of 78% and 77%, respectively, of these patients. The patients were immunized with the appropriate venoms over a 15-week course and most were then subjected to an in-hospital sting; there was a 3% reaction rate (1/37). Clinical protection as associated with a fivefold increase in anti-venom IgG. Five patients did not develop a significant increase in IgG antibody and they were treated more vigorously; four were stung subsequently without reaction. Two patients did not react when stung in the field; positive identification of the culprit insect was obtained. Twenty patients were re-stung after one year of maintenance therapy; there was a single mild, delayed reaction. Immunotherapy also increased the IgE antibody against venom 3.7-fold at three months; after one year of therapy the IgE antibody level had decreased but was still 40% greater than at the outset. Immunotherapy was associated with a 25% incidence of local pain and swelling and a 6% incidence of systemic reactions. We conclude that venom therapy in children is safe and effective. The indications for initiating immunotherapy require further definition.