Relationship of serum venom-specific IgE titers to clinical aspects of stinging insect allergy.

Fifty patients were randomly selected who had markedly elevated titers of serum venom-specific IgE (range 100-340 IU, mean 144 IU), and compared with 50 patients with low titers (range 0-50 IU, mean 25 IU). At the time serum was obtained, none of the patients had received venom immunotherapy (VIT). Analysis of the demographic data showed more children in the high-RAST group, and comparable matching of the groups for sex, presence of atopy, and culprit insect identification. The nature of the reaction preceding evaluation was similar in both groups. In the high-RAST group, there were 12 local, 15 mild systemic, and 23 severe systemic reactions. In the low-RAST group, there were 8 local, 15 mild systemic, and 27 severe systemic reactions. Other prior local reactions had occurred in 4 high-RAST and 4 low-RAST patients, and other prior systemic reactions had occurred in 3 high-RAST and 8 low-RAST patients. The incidence of systemic and local reactions following VIT was low in both groups. All but 1 patient in each group reached maintenance venom doses. Following initiation of VIT, 10 of 28 patients in the high-RAST group and 5 of 29 patients in the low-RAST group had a further rise in antibody titers. Patients in both groups showed a decrease in titers over a period of time, with or without VIT. Serum venom-specific IgG was greater in the high-RAST group (mean 9.4 U) than in the low-RAST group (mean 3.8 U). The absolute titers of serum venom-specific IgE appear unrelated to any specific feature of stinging insect sensitivity.