Chinese herbal medicine for atopic eczema

Abstract

Background: Traditional Chinese herbal mixtures have been used to treat atopic eczema for many years. Their efficacy has attracted public attention and recently some clinical trials have been undertaken.

Objectives: To assess the effects of Chinese herbal mixtures in the treatment of atopic eczema.

Search strategy: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) ( January 2004), the Cochrane Skin Group Specialised Register (January 2004), MEDLINE (1966 to January 2004), EMBASE (1980 to January 2004), CINHL (1980 to January 2004) and a number of complementary medicine databases. In addition, the cited references of all trials identified and key review articles were searched. Pharmaceutical companies involved in oral traditional Chinese herbs and experts in the field were contacted.

Selection criteria: Randomised controlled trials of Chinese herbal mixtures used in the treatment of atopic eczema.

Data collection and analysis: Two reviewers independently applied eligibility criteria, assessed the quality of the trials and extracted data. Any discrepancies were discussed to achieve consensus.

Main results: Four randomised controlled trials, with eight weeks for each phase, met the inclusion criteria. The trials randomised 159 participants aged from 1 to 60 years. The withdrawal rates ranged from 7.5% to 22.5% and no trial used intention to treat analysis. Three trials were randomised placebo controlled, two-phase cross-over designs assessing the same Chinese herbal mixture, Zemaphyte. In two of these three trials the reduction in erythema and surface damage was greater on Zemaphyte than on placebo, and participants slept better and itched less and expressed a preference for Zemaphyte. The fourth trial was an open-label design comparing Zemaphyte in herbal form with Zemaphyte as a freeze dried preparation. There was a reduction in erythema and surface damage with both formulations, but no comparison between the two formulations was reported. Some adverse effects were reported in all four trials, but none were regarded as serious.

Reviewers' conclusions: Chinese herbal mixtures may be effective in the treatment of atopic eczema. However, only four small poorly reported RCTs of the same product, Zemaphyte, were found and the results were heterogeneous. Further well-designed, larger scale trials are required, but Zemaphyte is no longer being manufactured.