Effect of Chinese herbal medicine injections for treatment of psoriasis vulgaris: a systematic review and meta-analysis

Background: Psoriasis vulgaris (PV) is a longstanding, inflammatory, immune-responsive skin condition. Chinese herbal medicine injections (CHMIs) have been utilized for treating PV in Asian countries. This study aims to conduct a thorough systematic review and meta-analysis to comprehensively appraise the efficacy of CHMIs in treating PV. Methods: Seven databases were searched for randomized controlled trials that evaluated the effect of CHMIs in treating PV, ranging from 2004 to June 2022. The meta-analysis was undertaken based on outcome measures, treatment options, and treatment durations using Review Manager 5.4. The primary outcome measure of this study was a 60% or higher reduction in the Psoriasis Area and Severity Index score (PASI 60). A descriptive analysis was performed for the assessment of adverse events. Results: This systematic review incorporated 33 studies, comprising 3,059 participants. The main findings indicated significant differences based on the PASI 60 (RR = 1.30, 95% CI: 1.24 to 1.37, Z = 10.72, p < 0.00001), PASI 30 (RR = 1.25, 95% CI: 1.13 to 1.38, Z = 4.48, p < 0.00001), and PASI 20 (RR = 1.28, 95% CI: 1.13 to 1.45, Z = 3.82, p = 0.0001) outcome measures. Evaluating the treatment options, CHMIs in combination with monotherapies like narrowband ultraviolet B (NB-UVB) and the acitretin capsule (AC) showed a greater reduction in PASI 60 (RR = 1.33, 95% CI: 1.25 to 1.43, Z = 8.32, p < 0.00001). In terms of treatment duration, no significant difference was observed when the duration extended beyond 56 days. Furthermore, the results suggested that CHMIs might reduce the incidence of adverse events in the treatment of PV. Conclusion: This systematic review revealed preliminary clinical evidence supporting the use of CHMIs for treating PV, considering outcome measures, treatment options, and treatment durations. However, due to the low methodological quality and limited sample size of the included studies, there is an urgent need for high-quality, multi-center and larger-scale studies of CHMIs for PV to provide robust evidence for their clinical application. Systematic Review Registration: [https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=326531], identifier [CRD42022326531].