Oral application of Chinese herbal medicine for allergic rhinitis: A systematic review and meta-analysis of randomized controlled trials

Chinese herbal medicine (CHM) has long been used for allergic rhinitis (AR). This systematic review aimed to investigate the clinical effects and safety of oral CHM for AR by comparing it to Western medications (WM). Nineteen databases were searched up to May 27, 2020. Randomized controlled trials (RCTs) assessing the effects of CHM on the primary or secondary outcomes comparing to WM, in any age of the patients, were included. The pooled results were expressed as mean difference, standardized mean difference, or odds ratio with 95% confidence intervals. Eighteen RCTs were included and 17 of them were evaluated in the meta-analysis. CHM may improve total nasal symptom scores, individual symptom scores (rhinorrhea, nasal congestion, sneezing, and nasal itching), quality of life, and recurrence rate, compared to antihistamines (loratadine and chlorpheniramine). Only mild and transient adverse events of CHM were reported. However, there were no significant differences in some subgroup analyses in total nasal symptom scores, rhinorrhea, nasal obstruction, sneezing, nasal itching, and SF-36. Due to the small number of included studies, poor quality of trial design, and substantial heterogeneities, the potential of CHM for AR should be validated in large, multicenter, and well-designed RCTs in the future.