Efficacy of allergen-specific immunotherapy for allergic rhinitis: a meta-analysis

Objective This meta-analysis aimed to systematically evaluate and compare treatment adherence (measured by treatment discontinuation rate) and safety (measured by adverse event rate) between subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT) in patients with allergic rhinitis (AR), providing evidence-based guidance for clinical decision-making. Methods A comprehensive literature search was conducted in PubMed, MEDLINE, Web of Science, Cochrane Library, and EMBASE databases from inception to August 2025 to identify relevant studies (specifically randomized controlled trials [RCTs]) comparing SCIT and SLIT for treating AR. Two independent researchers performed study selection and data extraction. The methodological quality of RCTs was evaluated using the Cochrane RoB-2 tool. Statistical analyses were performed using RevMan 5.3 and STATA 18.0. Dichotomous data were expressed as odds ratios (ORs), and continuous data were expressed as mean differences (MDs), both with 95% confidence intervals (CIs). Heterogeneity was assessed using the I 2 statistic. Publication bias and robustness of results were examined using Egger’s test and sensitivity analyses. Results This meta-analysis showed that there was no statistically significant difference in the treatment discontinuation rate between SCIT and SLIT in the treatment of allergic rhinitis (combined log OR = 0.30, 95% CI [−0.79, 1.39], p = 0.59); the incidence of adverse events in SCIT was significantly higher than that in SLIT (pooled log OR = 0.60, 95% CI [0.05, 1.15], p = 0.03), with a statistically significant difference. In clinical practice, the treatment plan can be selected based on patients’ preferences for treatment methods, their need for convenience, and the conditions for monitoring. Future large-sample long-term studies are needed for further validation of the findings. Conclusion Both SCIT and SLIT exhibited comparable treatment adherence (discontinuation rates) in patients with allergic rhinitis; however, the incidence of adverse events in SCIT was significantly higher than that in SLIT, and SLIT had more advantages in terms of safety. Clinical decisions should consider individual patient factors, including treatment convenience and monitoring conditions. Systematic review registration https://www.crd.york.ac.uk/prospero/display_record.php , identifier CRD420261306427.