Efficacy and Safety of Subcutaneous Immunotherapy for Local Allergic Rhinitis: A Meta-Analysis of Randomized Controlled Trials.

Background: Subcutaneous immunotherapy (SCIT) has been used for treating local allergic rhinitis (LAR) patients. However, the clinical efficacy and safety were still questioned.

Objective: This study was designed to estimate the efficacy and safety of SCIT for treating LAR patients through meta-analysis.

Methods: We systemically searched MEDLINE, Cochrane Library, and Embase publications. Randomized, double-blind, clinical trials for the efficacy and safety of Allergen Immunotherapy (AIT) for LAR were included. A meta-analysis of 4 clinical endpoints (combined symptom and medication scores [CSMS], symptom scores [SS], medication scores [MS] and rhinoconjunctivitis quality of life questionnaire [RQLQ]) and adverse events (AEs)) was performed after bias and heterogeneity assessments. The immunologic response results were summarized.

Results: Four RCTs with 134 patients were included. Four studies for analyzing primary outcomes (CSMS, SS, MS) and AEs, three for RQLQ results. The results indicated an important significant difference between SCIT and placebo groups, list as follows: CSMS (SMD = -2.42, 95% CI: -3.60 to -1.25,  < .0001), SS (SMD = -2.08, 95% CI -3.68 to -0.48,  = .01), MS (SMD = -1.43, 95% CI: -2.65 to -0.21,  = 0.02), RQLQ (SMD = -0.70, 95% CI -1.29 to -0.12,  = .02), Local AEs (RR = 4.13, 95% CI 1.08 to 15.77,  = .04). For immunologic response, significantly increased serum sIgG4 levels and improvements of allergen tolerance was observed after SCIT.

Conclusions: Our meta-analysis suggests that SCIT has a significant effect on improving symptoms and reducing medicine consumption for LAR patients. Larger and multicenter clinical trials are needed to clarify the safety and long-term efficacy.