Natural history of Hymenoptera venom allergy in children not treated with immunotherapy.

BACKGROUND: Differences in treatment approach still exist for children after systemic sting reactions. In addition, there are still some doubts about when systemic reactors should be treated with venom immunotherapy (VIT).

OBJECTIVE: To determine the rate of sting recurrence and natural history of Hymenoptera venom allergy (HVA) in children not treated with VIT.

METHODS: A total of 219 children diagnosed as having HVA who were not treated with VIT were identified in 3 pediatric allergology centers. Survey by telephone or mail with the use of a standardized questionnaire was conducted. The number of field re-stings, subsequent symptoms, and provided treatment were analyzed.

RESULTS: A total of 130 of the 219 patients responded to the survey, for a response rate of 59.4%. During the median follow-up period of 72 months (interquartile range, 52-85 months), 44 children (77% boys) were stung 62 times. Normal reactions were most common, occurring in 27 patients (62%). Severe systemic reactions (SSRs) occurred in 8 (18%) of those who were re-stung. The subsequent reaction was significantly milder (P < 0.001), especially in the case of patients re-stung by the same insect (P < .001). None of the children with prediagnostic large local reactions and negative test results for venom specific IgE developed SSRs after re-sting by the culprit insect (P = .03). In children with SSRs, median time from diagnosis to re-sting was 2 times longer than that in those with large local reactions and normal reactions (P = .007).

CONCLUSIONS: Most children with HVA not treated with VIT reported milder reactions after a re-sting. Probability of SSR to re-sting increases along with the severity of initial reaction.