Evaluation of efficacy and safety of topical application of Chinese herbal medicine for atopic eczema: a systematic review and protocol for pilot randomised double-blind placebo-controlled trial

摘要

Background: Atopic eczema (AE) or infantile eczema is an inflammatory skin disease, which affects 10-20% of children in industrialised countries. Australia was the 12th highest rank of AE incidence in 55 participating countries. AE is characterised by poorly demarcated redness of the skin and associated surface changes such as scaling, swelling, accentuation of the hair follicles and skin thickening as a result of chronic scratching. There are three common quoted diagnostic criteria for determination of AE for the purpose of research and clinical studies. In addition, reliable scoring instrument such as Scoring Atopic Dermatitis (SCORAD) is fundamental for clinicians to verify the severity, the course and outcomes of treatment for AE. Certain quality of life (QoL) questionnaires have also been developed and validated for assessment of the personal impact and outcomes of the treatment for AE. The conventional (Western) medicine treatment for AE is not satisfactory. Complementary and alternative medicine including Chinese herbal medicine (CHM) has been increasingly used for AE. There is some promising published evidence on oral administration of CHM for AE. However, the benefit of topical application of CHM for AE is not clear. Aims: a) To review fundamental knowledge of AE in perspectives of both conventional medicine and Chinese medicine (CM); b) To evaluate the effectiveness and safety of topical application of CHM for AE by systematically reviewing currently available randomised controlled trials (RCTs); and c) To develop a protocol for pilot randomised double-blind placebo-controlled clinical trial for evaluation of the efficacy and safety of topical application of CHM for AE. Methods: We searched any RCTs with topical application of CHM in electronic databases and journals. Trial-design quality was evaluated and intervention outcome data were extracted and analysed. Meta-analysis was conducted. Development of a protocol for pilot RCT of topical application of CHM for AE followed the Australian Government’s guidelines in compliance with high ethical standard. Results: Three studies involving a total of 452 participants were selected for analysis after screening 164 potential studies. All three included studies reported significant differences between the treatment group and controlled group and claimed that effects of treatment interventions were superior to control. However, due to the low quality of study design which resulted in low level of evidence strength, these claims require more vigorous scientific proof employing well designed RCTs. As a result, a protocol for pilot randomised double-blind placebo-controlled clinical trial for evaluation of the efficacy and safety of topical application of CHM for AE was developed. Conclusion: The systematic review in this thesis is the first one conducted in topical application of CHM for AE. Detailed analysis of the three included studies led to the conclusion of low level of evidence strength. Thus, they did not provide convincing evidential support for effectiveness of CHM used topically for AE or infantile eczema. Therefore, there is a need to evaluate the efficacy and safety of topical application of a CHM for AE through a well designed, double-blind controlled-placebo clinical trial.