Sani S, et al. - Via this 10-year retrospective chart review of 459 patients treated with subcutaneous allergen immunotherapy (SCIT), researchers investigated the rate of systemic reactions (SRs) to SCIT, and determined risk factors related to SR development. Based on age, patients were allocated to cohorts of pediatric (5-18 years), adult (19-64 years), and senior (> 65 years) patients. They detected an SR (N = 177) in 24.8% of the patients (n = 114). The reported incidence of SR per injection was 0.2%. Using the 2010 World Allergy Organization's SR grading system, they defined SRs as class 1 (n = 152), class 2 (n = 21), class 3 (n = 2), and class 4 (n = 2). They noted no variations existed in the number of SRs with respect to age group. Female patients, patients with a history of drug or food allergies, and those who were receiving pet or dust-mite SCIT predominantly experienced SRs to SCIT in this patient population.