This systematic review examines the current state of the evidence for the efficacy and safety of herbal medicines (HMs) used topically in conjunction with anti-psoriatic pharmacotherapy (APP) in the treatment of psoriasis. Searches were conducted in September 2012 of PubMed, EMBASE, Cochrane Library, two Chinese databases (China National Knowledge Infrastructure and Chinese Scientific Journals Full Text Database) and of article reference lists. We included randomized controlled trials published in English, Chinese or Japanese that investigated topical HM combined with APP used systemically and/or topically compared to pharmacotherapy alone. Studies employing phototherapy were excluded. Two authors conducted searches, extracted data on study characteristics and outcomes, and assessed Risk of Bias. Disagreements were resolved by discussion with a third author. Eight studies met the inclusion criteria. All used multi-herb formulae, four in herbal baths, three in herbal ointments or creams, and one as herbal steam. The pooled data indicated a benefit for the add-on effect of herbal therapy to APP. Adding these topical HMs to conventional pharmacotherapy appeared to produce short-term additional clinical benefits. No serious adverse events were reported. Experimental studies suggest that some of the herbs possess anti-inflammatory, anti-pruritic, and/or anti-proliferative activities. However, these results need to be interpreted with caution due to methodological weaknesses and the lack of replicated studies. Studies that address the identified methodological deficiencies are required to further investigate the efficacy and safety of these HMs as adjunct therapies for psoriasis.
