The add-on effect of oral East Asian herbal medicine to steroid therapy for alopecia areata: A systematic review and meta-analysis

Introduction: Alopecia areata (AA) is an autoimmune disease that degrades patients' quality of life and adversely affects mental health. Since steroid therapy (ST) has limited efficacy and a risk of recurrence, East Asian herbal medicine (EAHM) combined with ST has been suggested as an alternative treatment. Many randomized controlled trials (RCTs) have been conducted on the efficacy of EAHM combined with ST in AA treatment; however, the efficacy of EAHM combined with ST and the treatment effects of ST alone have not yet been compared. This systematic review and meta-analysis aimed to evaluate the effectiveness and safety of the combination of ST and EAHM compared to ST alone in the treatment of AA. Methods: We searched 10 databases: PubMed, EMBASE, Cochrane Library, China National Knowledge Infrastructure (CNKI), Wanfang, KoreaMed, Korean Medical Database (KMBASE), Korean Studies Information Service System (KISS), ScienceON, and Korea Science. Bias was independently assessed using Cochrane Risk of Bias tool (RoB 2.0), and meta-analysis was conducted using Review Manager (Revman) 5.4.1 with the application of random-effect models. The primary outcome was defined as the cure rate. Results: Fifteen studies were selected, and 1,119 participants were included in the study. According to the results of the meta-analysis, a higher cure rate (RR 1.50, 95 % CI : 1.31, 1.71, P<0.00001, I²=0 %), a higher total efficacy rate (modified Total Efficacy Rate 1 (mTER1); (RR 1.10, 95 % CI: 1,06, 1.15, P < 0.00001, I²=0 %), modified Total Efficacy Rate 2 (mTER2); (RR 1.09, 95 % CI: 1.03, 1.16, P = 0.006, I²=0 %)), and a lower recurrence rate (RR 0.28, 95 % CI: 0.16, 0.48, P<0.00001, I²=0 % %) were confirmed in the ST with EAHM group than in the ST group. Low IFN-γ levels and high IL-10 levels were identified in the ST combined with EAHM group. No serious adverse effects were observed during treatment. Conclusions: Compared to ST alone in AA treatment, the combination treatment of ST and EAHM may effectively and safely increase the cure and total efficacy rates and may lower the recurrence rate. However, to strengthen the basis of this review, higher quality RCTs must be performed.