A recent study has confirmed the safety and efficacy of subcutaneous venom immunotherapy (VIT) for children suffering from Hymenoptera venom allergies. Conducted by a team led by Mattia Giovannini at the University of Florence and the Allergy Unit at Meyer Children’s Hospital IRCCS, the research highlights the treatment’s low rate of systemic reactions and its role as a crucial therapeutic option for pediatric patients.
The study analyzed the medical records of 58 children diagnosed with venom allergies who received VIT between 1997 and 2021. Among the patients, 87.9% were male, with a median age of 9.4 years. The median duration of VIT was 5.4 years, and on average, each patient received 63.4 injections. The findings revealed that nearly half of the participants had a positive family history of atopy, a condition often linked to allergic reactions.
Study Findings and Methodology
The researchers aimed to evaluate VIT’s safety, assess the factors leading to adverse reactions, and determine the effectiveness of the treatment following re-stings. Utilizing a retrospective analysis, the team classified a total of 3739 injections and recorded 335 adverse reactions, translating to a 9.5% occurrence rate. Most of these reactions were localized (8.2%), with systemic reactions occurring in just 0.4% of cases.
During the buildup phase of the treatment, which included 1120 injections, 194 adverse reactions were documented. The maintenance phase accounted for 2619 injections and reported 161 adverse events. Notably, the buildup phase showed a significantly higher incidence of adverse reactions compared to the maintenance phase (P < .0001). No significant differences were found in the rates of extended local reactions or systemic reactions between the two phases. The study evaluated the effectiveness of four venom extracts: Apis mellifera (28.4%), Vespula (33.3%), Polistes (33.3%), and Vespa crabro (5%). It found that systemic reactions were most prevalent during the treatment with Polistes venom, at a rate of 0.5%.
Implications for Venom Allergy Treatment
The research also examined the ability of patients to correctly identify insect species, which plays a critical role in selecting the appropriate VIT extract. Participants could easily distinguish Apis mellifera and Vespa crabro but faced challenges differentiating between Vespula and Polistes both before and after treatment initiation.
Out of the cohort, 31 patients experienced 51 re-stings after completing VIT, with only 2 patients (3.9%) suffering systemic reactions, which were linked to different Hymenoptera species than those targeted during therapy. The findings indicate that VIT demonstrates both safety and efficacy, even in cases of re-stinging.
In conclusion, the study corroborates that VIT, particularly the cluster protocol, is a safe and effective treatment for pediatric patients with Hymenoptera venom allergies. The investigators remarked that while the buildup phase is associated with a higher frequency of adverse reactions, factors such as sex, age at initiation, and family history of atopy did not significantly influence the risk of adverse events. These insights underscore the importance of VIT as a foundational therapy for those with venom allergies, paving the way for improved management of this potentially life-threatening condition.
For further details, the complete study is published in Pediatric Allergy and Immunology.