Mustafa SS, et al. - Given that despite the reported occurrence of local reactions (LR) to subcutaneous immunotherapy (SCIT) in 26-86% of patients, there exist no well-examined strategies to treat LRs, and therefore, researchers compared pre-rinsing SCIT syringes with diphenhydramine, epinephrine, or placebo in patients taking aeroallergen SCIT and encountering LRs despite pretreatment with an antihistamine, in this prospective, randomized, single-blind, controlled trial. The participants, aged ≥ 5 years, were randomized to diphenhydramine, epinephrine, or placebo rinse, and were observed for three subsequent visits. Findings revealed the efficacy of an epinephrine rinse in significantly reducing LR at the first visit in patients who took aeroallergen SCIT per a conventional dosing schedule, and also within a sample that described a consistent outcome at all three study visits. Results also revealed the safety as well as the effectiveness of adding an epinephrine rinse for reducing LRs to aeroallergen SCIT in patients already premedicated with an oral antihistamine.