Evaluation of Hymenoptera-sting sensitivity with deliberate sting challenges: inadequacy of present diagnostic methods

Abstract

We administered deliberate sting challenges to 21 patients, five of whom had histories of large local (LL) reactions and 16 of whom had previous systemic (SYS) reactions to stings. Eleven had been treated previously with whole-body extract, but none had received venom immunotherapy. Immediately before sting challenges with honeybees, wasps, yellow jackets, yellow hornets, and white-faced hornets, we performed skin tests and measured serum IgE antibody levels with venoms from these five insects. In addition, we measured IgG antibody levels to honeybee, yellow jacket, and white-faced hornet venoms. In the LL group, 14 21 skin tests were negative, but in the SYS group 30 34 skin tests were positive prior to the deliberate sting. IgE antibody levels (expressed as percent of binding compared with serum from a nonsensitive individual) ranged from 63% to 789% and 66% to 801% for the LL and SYS groups, respectively. IgG antibodies ranged from <5 to 332 U/ml, and levels were similar for the LL and SYS groups. Fifty-five sting challenges were administered; seven generalized reactions were induced and occurred only in the SYS group. Seven individuals (three LL, four SYS) who tolerated the first series of stings returned for a second series of sting challenges with the same insects. Of these seven, 10 15 skin tests were now positive in the LL group; 10 12 skin tests were now positive in the SYS group. IgE antibody levels ranged from 103% to 737% and 85% to 2389% for the LL and SYS groups, respectively, prior to the second series of sting challenges; IgG antibody levels were again similar in both groups. All repeat challenges were tolerated without generalized reactions. No in vitro or in vivo test predicted with certainty the clinical immune status of a sting-sensitive person.