Maintenance venom immunotherapy administered at 3-month intervals is both safe and efficacious

Background: Maintenance venom immunotherapy (MVIT) is usually administered to patients with venom allergy at 4- to 6-week intervals for at least 3 to 5 years, The small number of studies assessing the possibility of extending the maintenance interval (MI) included either too small a population and p atients with only vespid and not bee venom (BV) allergy or relied on reacti on to field stings only Objective: We sought to assess the safety and efficacy of MVIT given at 3-m onth intervals to a large population of patients allergic to both yellow ja cket venom and BV, Methods: In all patients undergoing venom immunotherapy, MI was gradually e xtended to 3 months, Systemic reactions (SRs) to immunotherapy injections o r to field stings were regularly recorded. Some of the patients were also d eliberately sting challenged during the 3-month interval. Patients disconti nuing MVIT were interviewed regarding their responses to field re-stings, a nd in some of them, an in-hospital sting challenge was performed, Results: One hundred sixty patients mostly allergic to BV were enrolled in the study, Failure to reach the 3-month interval was observed in 6 (3.8%) p atients, originating in failure to reach the full maintenance dose in most of them. SRs to MVIT administered at 3-month intervals were observed in 2.6 % of the patients. One of 36 patients who experienced a field sting during the 3-month interval had an objective mild SR (2.8%). Two (4.5%) of 44 pati ents who were deliberately stung during the 3-month interval had mild SRs, After discontinuation of MVIT, 2 (8.3%) of 24 patients who experienced a fi eld sting had an SR. Both were allergic to yellow jacket venom, Three to 82 months after discontinuation of MVIT, 22 patients allergic to BV were stin g challenged. Only one (4.5%) patient had a mild objective SR, Conclusions: The conventional 4- to 6-week MI can easily be extended to 3 m onths in most patients without any adverse events. MVIT given at a 3-month interval is safe and effective while being administered, as well as after i ts discontinuation. This fact should be applied to almost every patient all ergic to insect venom,