[Observation of systemic adverse reactions by specific immunotherapy and analysis of risk factors in allergic rhinitis].

Objective: To investigate the systemic adverse effects of specific subcutaneous immunotherapy (SCIT) in patients with allergic rhinitis (AR) and explore the possible risk factors. Methods: A retrospective study was conducted on AR patients who underwent SCIT from January 2014 to January 2017 in Department of Otorhinolaryngology, the First Affiliated Hospital of Chongqing Medical University. For patients with adverse reactions, the detailed medical history during treatment was reviewed. Results: A total of 1608 injections were performed on 102 patients, there were 12 cases / 21 times systemic adverse events, including systemic urticaria, angioedema and Grade Ⅰ systemic adverse reactions. There were 3 cases of grade Ⅳ adverse reactions. Systemic adverse reaction was prone to an initial treatment phase where the dose and concentration of the injection were increasing. Meanwhile, it was more common in young patients aged 20-40 years old and easy to occur in May and June. About the possible risk factors, the most common one was obvious local adverse reactions (17/21), followed by prolonged injection interval (9/21), the recent exposure to a large number of allergens (7/21) and strong positive skin prick results (7/21). Conclusions: The systemic adverse effects, which were induced by SCIT, mainly included systemic urticaria, angioedema and Grade Ⅰ systemic adverse reactions. Systemic adverse reaction was prone to an initial treatment phase where the dose and concentration of the injection were increasing.