• insect allergy;
  • natural history;
  • risk factor;
  • time interval

The aim of the study was to determine whether a short interval (<2 months) between two consecutive stings influences the development of Hymenoptera venom allergy. The study compared the sting-interval distribution in 120 allergic patients who experienced a first-time systemic reaction to a Hymenoptera sting, and in 100 healthy controls. A significant difference in sting-interval distribution between the two groups was found (P= 0.0001). In 71 of 120 allergic patients, the sting that provoked the systemic reaction had been preceded by another, completely tolerated sting not more than 2 months before. However, in the control group only four subjects out of 100 had received two consecutive stings within less than 2 months. In conclusion, a short interval between two consecutive stings seems to be a risk factor for the onset of Hymenoptera venom allergy.