Evaluation of the safety and efficacy of Chinese medicine treatment in the management of atopic dermatitis

摘要

Atopic dermatitis (AD) is a chronic, inflammatory skin rash which affects approximately 15-30% of children and 2-10% of adults and can significantly impair quality of life. The extended use of their mainstay therapies may lead to local and systemic adverse events and the development of drug tolerance. Treatment via Traditional Chinese medicine (TCM) has shown promising effects. However, systematic reviews (SRs) have deemed the overall studies to be of “poor quality”, resulting in insufficient evidence for valid conclusions. This thesis aims to systematically review the classical and modern literature to evaluate the efficacy and safety of TCM therapies for the management of AD; and design a rigorous randomised controlled trial (RCT) to evaluate a newly formulated Chinese herbal medicine (CHM) formula, RCM-106. The review of the classical literature was conducted using the database software, Zhong Hua Yi Dian (ZHYD). “Si Wan Feng” and “Nai Xuan” had the closest descriptions resembling AD. The main TCM treatment was CHM, with the majority including herbs that cleared damp and heat according to TCM theories, which matches one of the common diagnoses for AD. The comprehensive review identified studies from the English and Chinese electronic databases. Majority of the RCTs were poor quality as they lacked the use of validated diagnostic criteria and outcome measure instruments, and had inadequate reporting. Comparatively, Chinese studies tended to be more pragmatic, resulting in more methodological issues when compared to explanatory studies. However, this approach more accurately reflects the clinical practice of TCM. A SR on orally-administered CHM for AD and another on acupuncture for AD were conducted according to the Cochrane Handbook. While both SRs showed potential benefits, the overall evidence was insufficient to support valid conclusions. The reviews contributed to the formulation of RCM-106 for AD and the design of a rigorous RCT. The RCT protocol is for a parallel-armed, placebo-controlled, double-blind clinical trial involving children, aged 6-18, with moderate-to-severe AD. This protocol was made to suit the paediatric population as its target participants. The protocol has human ethics approval from the Human Research Ethics Committee of RMIT University and conforms to World Health Organisation (WHO), Food and Drug Administration (FDA) and Therapeutic Goods Administration (TGA) guidelines, as well as guidelines for safe dosages of CHM for the paediatric population. Extra safety precautions were included, such as a “swallow-test” during screening of participants, and an optional “capsule swallowing training program”. Furthermore, verbal assent from participants, in addition to written consent from their legal guardian, would be sought. It is anticipated that this protocol will act as a guide for future studies and that the results of the study will open doors to future larger-scaled RCTs and pharmacological studies of RCM-106. Future research needs to be directed towards the better understanding of the pharmacology of CHM and how it relates to TCM theories. As AD mainly affects children, studies should also focus on the pharmacokinetics of the commonly-used herbs in the paediatric population to enable a more sound evaluation of the efficacy and safety of CHM treatment.