692 VENOM IMMUNOTHERAPY FOR INSECT HYPERSENSITIVITY

Abstract

Twenty-five children with histories of hypotension, respiratory distress or a marked generalized cutaneous response following a sting by insects of the Hymenoptera order were selected after fully informed (familial) consent, for a trial of immunotherapy with insect venom. As indicated by venom skin tests, IgE antibody measurements and leukocyte histamine release, five were sensitive to only honeybee venom, thirteen to vespids (yellow jacket, white-faced hornet, yellow hornet) and seven to both species; each child was treated over 4-5 months by injections of each appropriate venom, reaching a maintenance dose, previously established in adults, of 100 μg. Routine toxicity studies were carried out, without significant abnormalities being noted. Radioimmunoassays for antibodies to honeybee venom phospholipase A and yellow jacket venom indicated that all children had an increase in IgG (5-25fold) which had usually peaked at the time of challenge. Three children were stung in the field by the appropriate insect without sequelae. The clinical protection of the remaining twenty children was assessed by deliberate sting by the appropriate insect(s) in an emergency room setting. Without therapy 12 reactions were expected; none were observed. This is the first study which shows that venom immunotherapy is well tolerated and clinically protects insect sensitive children.