Efficacy and safety of subcutaneous venom immunotherapy in children: A 24-year experience in a pediatric tertiary care center

Abstract

Background: Hymenoptera venom allergy is a significant cause of morbidity and mortality, also in pediatric patients, highlighting the importance of effective management through venom immunotherapy (VIT). This study aimed to evaluate the safety profile of VIT, identify factors associated with adverse reactions (ARs), assess the accuracy of insect identification and its impact on VIT extract selection, and determine treatment efficacy by analyzing ARs following re-sting. Methods: The medical charts of patients followed up at the Allergy Unit of Meyer Children's Hospital IRCCS, Florence, Italy, who completed a VIT cycle between 1997 and 2021 were retrospectively analyzed. VIT extract selection was guided by a diagnostic workup following the European Academy of Allergy and Clinical Immunology guidelines and the Italian Consensus on Hymenoptera venom allergy management. We implemented a cluster protocol and adjusted it as needed for ARs during VIT. Results: Fifty-eight patients, from a total of 60 VIT (2 patients underwent VIT for both Vespula and Polistes) were included, using the following extracts: 17 Apis mellifera (28.4%), 20 Vespula (33.3%), 20 Polistes (33.3%), and 3 Vespa crabro (5.0%). Upon the 3739 injections administered, 355 ARs (9.5%) occurred: local reactions (LRs), 306 (8.2%); extended local reactions (ELRs), 34 (0.9%); and systemic reactions (SRs), 15 (0.4%). The build-up phase was associated with a higher number of ARs and LRs compared with the maintenance phase during VIT (p