Longdan Xiegan formula as adjuvant therapy for acute herpes zoster: A meta-analysis of randomized controlled trials

Longdan Xiegan (LDXG) decoction, an ancient Chinese herbal formula, has been widely used in treating herpes zoster. This meta-analysis aimed to evaluate whether LDXG formula as adjuvant therapy had additional benefits in acute herpes zoster patients. Two authors independently searched PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, Chinese Scientific Journal Database, and Wanfang database from their inception to July 31, 2021. Relevant randomized controlled trials (RCTs) that investigated the add-on effects of LDXG formula (decoction, capsule, or pill) in the management of acute herpes zoster were included. Nine RCTs with 821 patients were identified. A random effect model meta-analyses showed that LDXG formula plus conventional therapy significantly reduced the time to blister resolution (weighted mean difference [WMD] -1.31 days; 95% confidence intervals [CI] -1.56 to -1.06), time to crust formation (WMD -1.91 days; 95% CI -2.31 to -1.50), time to pain resolution (WMD -2.13 days; 95% CI -2.65 to -1.60), pain intensity assessed by visual analogue scale (WMD -1.13; 95% CI -2.03 to -0.24), and incidence of persistent pain (risk ratio [RR] 0.28; 95% CI 0.15-0.50) compared with the conventional therapy alone. However, the overall certainty of evidence was very low to moderate. LDXG formula as adjuvant therapy may achieve additional benefits in terms of accelerating skin healing process, relieving pain symptoms, and preventing persistent pain in acute herpes zoster patients. However, interpretation of these findings should be considered the presence of statistical heterogeneity and/or unclear risk of bias.