This critical review of randomized controlled trials (RTCs) was conducted to evaluate the efficacy and safety of herbal products used in the topical treatment of psoriasis.

Selected databases were systematically searched using keywords. RCTs focusing on mild to moderate psoriasis using herbal topical treatments in comparison either to standard medications or placebo were included. The methodological and reporting quality of included trials was assessed through Cochrane Risk of Bias 2.0 tool (ROB2) and Consolidated Standards of Reporting Trials (CONSORT) 2010 statement (with elaborations for herbal interventions), respectively. Meta-analysis was conducted via Review Manager (RevMan) 5.4 software. 14 RCTs published from 2010 to 2020 were included in this review.

There is some evidence to suggest that topical herbal treatments are useful in the treatment of psoriasis. The meta-analysis favoured herbal treatment over conventional medicines and placebo and the herbal treatments caused fewer side effects. Indigo naturalis L. oil, Hypericum perforatum (Hypericaceae) and Curcuma longa L. Zingiberaceae (Turmeric) were particularly promising, due to their possible anti-inflammatory effects.

There is some evidence to suggest the use of topical herbal medicines in the treatment of psoriasis. However, the quality of included RCTs was poor and at a higher risk of bias in many domains. Therefore, larger, better designed and long-term RCTs should be conducted to enhance the quality of the evidence.