Background: Severity of a previous reaction, adult age, male gender and honeybee sting are risk factors for severe systemic reactions after hymenoptera stings. The aim of the study was to assess the association between the Vespa crabro sting and severe systemic reactions.
Methods: One hundred fifty seven hymenoptera allergic patients with a positive case history for systemic reactions were selected on the basis of unequivocal identification of the stinging insect. In 97 patients the culprit insect was Vespula spp., in 35 was Vespa crabro in the remaining 25 patients was Apis mellifera. The relative risk for a life-threatening reactions after a sting was evaluated for each hymenoptera species.
Results: While the percentage of life-threatening reactions was similar both in Apis mellifera (24%) and in Vespula spp. Allergic patients groups (27.8%), a very high prevalence (81.2%) was documented in Vespa crabro allergic patients group. The relative risk for life-threatening reactions after a Vespa crabro sting was about three times higher (RR = 2.74--CI 95% 1.93-3.89--R < 0.0001) than it was for a honeybee or yellow jacket sting. The increase of the risk for life-threatening reactions after a Vespa crabro sting was independent from the age of patients.
Conclusion: Vespa crabro sting seems to be a new risk factor for life-threatening reactions after hymenoptera sting.