Subcutaneous immunotherapy with aeroallergens: safety profile assessment

Introduction. Severe systemic reactions (SR) to allergen subcutaneous immunotherapy (SCIT) are rare but local reactions (LR) are common. We aimed to characterize the type of reactions and safety profile. Methods. Retrospective analysis of medical record from patients under SCIT between 2013-2016. Results. Total of 7372 SCIT injections in 323 patients: 52% female; mean age 30 years (SD 13); mean treatment time 19 months (SD 13). There were 57 patients (17.6% of population, 70% female) with at least one adverse reaction, for 93 reactions described (1.3% injections). There were 79 LR (1.1% injections) in 46 (14.2%) patients: 36 in build-up, 43 in maintenance. There were 14 SR (0.19% injections) in 12 (3.7%) patients: 12 in build-up, 2 in maintenance. All SR were grade 1. The majority of reactions were caused by mite SCIT (69.9%). Conclusions. SCIT is safe and well tolerated, with no report of SR grade > 1.