SYSTEMIC REACTIONS TO SCIT: EFFECTS OF DOSING AND AEROALLERGEN CONTENT

Abstract

Introduction The aim of this study was to identify the dose of subcutaneous immunotherapy (SCIT) that caused the most systemic reactions (SCITSR), and identify any other risk factors for SCITSR. Methods We performed a retrospective review of all SCIT encounters from 2013-2017 at a multi-site Allergy/Immunology practice. SCIT was administered in doses consistent with practice parameters. SCITSR were identified through immunotherapy encounters in which epinephrine was administered. Collected data included patient demographics, along with the dose of SCIT at time of the SR, the presence or absence of asthma, and aeroallergen content. The control group was generated randomly from the same cohort during the same time period. Results There were 86,949 SCIT visits, with 81 SCITSR (0.9/1000). 77.8% of reactions occurred at dose of 1:1 0.1 ml and above. The presence of cat (81.5% vs. 63%, p=.014), dog (67.9% vs. 37.0%, p Conclusions Risk factors for SCITSR in a multisite Allergy/Immunology practice included administration of the highest immunotherapy doses, inclusion of cat, dog, and grass extracts, and the number of aeroallergenic groups included in the extract. This information helps further characterize risk for patients receiving SCIT.