RESUMO
BACKGROUND AND OBJECTIVE: The purpose of this study was to describe the clinical and epidemiological features of anaphylactic reactions to hymenoptera stings, with a case-history analysis according to severity. PATIENTS AND METHOD: We conducted an observational descriptive study of patients aged between 10 and 80 years who suffered a systemic reaction after hymenoptera sting. All of them showed specific serum IgE to venoms from Apis, Vespula and/or Polistes. A questionnaire including history of atopy, past reactions and characteristics of the reaction, was performed by individual interview. Anaphylactic reactions were classified into two levels of severity according to Müller's classification. An analysis of independence was carried out in order to relate each level with several factors: age, gender, atopy, type of previous reactions, area of sting and time sequence. RESULTS: 113 patients were included (63 male; mean age [standard deviation]: 40.1 [15.9] years). Reactions were accounted for bee venom in 10.6% of patients, and wasp in 89.4%. Specific IgE was positive to Vespula in 91.9% of subjects, Polistes in 71.4%, and Apis in 28.7%. Furthermore, 50.4% were sensitive to both Vespula and Polistes. Personal history of atopy was found in 20.3%. Among the 106 patients who reminded previous stings, local large reactions were referred by 35.9% and systemic reactions by 16.5%. Upper limb was the most frequent area of sting (38.9%). Most common symptoms were: pruritus (77.8%), hives (57.5%), edema (54.8%), erythema (52.2%), dizziness (51.3%) and dyspnea (49.5%). Severe reactions occurred in 65.5% of patients. Age, gender, atopy, type of previous reactions, area of sting and restoration time were not significantly associated with severity. Time elapsed to first symptom was proportionally shorter in severe cases (p < 0.05). CONCLUSIONS: There is a high frequency of hypersensitivity to wasp venom (Vespula) in the studied population. Except for immediacy, severity-associated data could not be established.