A recent investigation 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 from the University of Florence and Meyer Children’s Hospital IRCCS in Florence, Italy, the study revealed a low systemic reaction rate of just 0.4% among participants, with none requiring epinephrine.
The findings, published in the journal *Pediatric Allergy and Immunology*, underscore VIT as the only proven treatment for patients with a history of severe reactions to insect stings. Previous research has established the overall safety of venom immunotherapy, but limited data has been available on adverse reactions in pediatric patients.
Study Overview and Patient Demographics
To evaluate VIT’s safety and effectiveness, the researchers retrospectively analyzed the medical records of 58 patients under the age of 18 who received VIT between 1997 and 2021. The cohort was predominantly male, with approximately 87.9% identifying as male and a median age of 9.4 years.
The duration of VIT treatment averaged 5.4 years, and patients received a median of 63.4 injections. Notably, 47.7% of the participants had a positive family history of atopy, while 27.6% exhibited atopic conditions, including rhinoconjunctivitis, asthma, food allergies, and atopic dermatitis.
A diagnostic workup in accordance with European guidelines guided the selection of VIT extracts for the patients. The study examined four different venom extracts: Apis mellifera (28.4%), Vespula (33.3%), Polistes (33.3%), and Vespa crabro (5%).
Adverse Reactions and Treatment Efficacy
Throughout the study, a total of 3,739 injections were administered, resulting in 335 adverse reactions, equating to a rate of 9.5%. These reactions were classified primarily as local (8.2%), extended local (0.9%), and systemic (0.4%).
During the build-up phase, clinicians administered 1,120 injections, recording 194 adverse reactions; the maintenance phase included 2,619 injections with 161 adverse events. The build-up phase was associated with a significantly greater frequency of adverse reactions compared to the maintenance phase, with a p-value of P < .0001.
Interestingly, the study found that males experienced a lower risk of adverse reactions compared to females. Additionally, systemic reactions were most commonly associated with the Polistes venom, which had a rate of 0.5%. There were no significant differences in allergic reactions across the various venom extracts.
Among the participants, 31 patients experienced 51 re-stings after VIT treatment, with only 2 (or 3.9%) reporting systemic reactions. These reactions arose from different Hymenoptera species than those targeted during the VIT.
The study also highlighted a challenge in insect identification, noting that while patients could easily recognize Apis mellifera and Vespa crabro, they struggled to distinguish between Vespula and Polistes before and after initiating VIT.
In conclusion, the findings indicate that VIT using a cluster protocol is both safe and effective for pediatric patients with venom allergies. The study emphasizes the treatment’s low rate of systemic reactions, particularly highlighting the need for further research on the varying reactions among different venom types. As stated by the investigators, “VIT demonstrated indisputable efficacy upon re-stinging, underscoring its value as an essential therapy for eligible patients.”
