Background In this study, which summarizes our last 5 years of experience, we evaluated the side-effects of ultra-rush venom immunotherapy and the possibility to define some risk factors for side-effects as age, Hymenoptera venom used for treatment, treatment phase, severity of prior insect sting reaction, concentration of skin test positivity, and level of specific IgE.
Methods In our protocol on day 1, an initial venom dose of 0.1 μg was followed by 1, 10, 20 μg at 30-min intervals and then 30 and 40 μg at 60-min intervals. Patients who completed this protocol received two booster injections of 50 μg on day 15 and one of 100 μg on day 45. Subsequently, monthly 100 μg boosters were given.
Results Fifty-one children (9.20 ± 3.41 years) and 207 adults (40.62 ± 14.00 years) underwent an ultra-rapid venom immunotherapy (ultra-RVIT). Single ultra-RVIT was administered to 195 patients: 69 with honeybee, 123 with yellow jacket and three with wasp venoms. Two venoms were injected into 59 patients: 42 with yellow jacket and wasp, 17 with yellow jacket and honeybee. Four patients received the three venoms.
The frequency of immediate systemic reactions (SR) was not significantly different between adults and children: 11.2% vs. 10.8%.
SR were experienced more frequently on day 1 (n= 33). They were uncommon on day 15 (n= 2) and on day 45 (n= 1). No late reactions have been observed. Honeybee venom induced significantly more SR (30%) vs. yellow jacket (3.2%) and wasp venom (6.1%). Among the 33 patients who experienced a SR on day 1, 24 had a reaction grade 1 or 2 and nine had a reaction grade 3 or 4. There is a significant risk for patients with a prior reaction grade 3 or 4 to experience a SR during venom immunotherapy (VIT).
The strength of positive skin tests and the level of specific IgE were not related to an increased risk of SR (P= NS).
Conclusion Treatment with honeybee extract induced more SR than the treatment with yellow jacket and wasp venom. Doses increase phase on day 1 is risk factors for SR of ultra-RVIT, as well as the severity of the prior reaction. Age, degree of positive skin tests, and specific IgE are not risk factors.