The prevalence of insect venom allergy in the European population is approximately 5%. Hymenoptera venom allergy is an important epidemiological problem. Ten to 40 deaths are reported annually in Germany. In contrast to conventional dose increase schedules lasting a minimum of 5 days, shorter protocols reduce the patient's stay in the hospital and provide an earlier protection toward stings. Clinical studies on ultrarush protocols have been published for adult patients, but very little data are currently available for children. Therefore, we investigated the safety and tolerability of a shortened insect venom immunotherapy (VIT) in children and adolescents. Forty-three children and adolescents (aged 4-18 years) with insect venom allergy were treated in this study. Five children were hyposensitized according to the ultrarush protocol with nine injections (as suggested by Brehler et al. (Safety of a two-day ultrarush insect VIT protocol in comparison with protocols of longer duration and involving a larger number of injections. J Allergy Clin Immunol 105:1231-1235,2000); 38 children received the modified ultrarush schedules with only eight subcutaneous injections. With both protocols the maintenance dose (100 microg) was achieved in 24 hours. Twenty-five patients (58.1%) showed no reaction after the injections. In 11 patients (25.6%), extensive erythema (>5 cm, maximum of 20 cm) was found at the injection site. Erythema and edema (>5 cm, maximum of 15 cm) were observed in seven patients (16.2%). The maintenance dose was well tolerated, with no systemic reaction in any patient. The modified ultrarush protocol for insect VIT used in this study showed very good tolerability and safety in children and adolescents. This dose regimen can increase compliance by shortening inpatient stay and reduces hospital costs.