Oral Taodan granules for mild-to-moderate psoriasis vulgaris: protocol for a randomized, double-blind, multicenter clinical trial

BACKGROUND: Psoriasis is a common chronic inflammatory skin disease with high recurrence rates and increasing incidence. Patients require long-term medication to reduce symptoms and prevent disease progression. Therefore, the development of treatments with high efficiency and low rate of adverse events is of utmost importance. Traditional Chinese medicine (TCM) plays an outstanding role in reducing disease symptoms and improving quality of life. The aim of this trial is to clarify the treatment efficacy, safety, and control of disease recurrence in patients with psoriasis with blood-stasis syndrome treated with Taodan granules (TDKL). METHODS: This trial is a five-center, randomized, double-blind, placebo-controlled study planned to transpire between September 1, 2019, and December 31, 2021. A sample size of 216 participants (108 per group) with mild-to-moderate psoriasis will be randomly assigned to receive TDKL or placebo twice per day, 7 days per week, for 8 weeks. The study duration will be 17 weeks, including a 1-week screening period, 8 weeks of intervention, and another 8 weeks of follow-up. The primary outcomes are improvement in the Psoriasis Area and Severity Index score and recurrence rate after 8 weeks of treatment. Secondary outcomes include body surface area affected and the scores for the Physician Global Assessment, Dermatology Life Quality Index, pain-related quality of life, pain on the visual analogue scale, and TCM syndromes. The number, nature, and severity of adverse events will be carefully recorded. DISCUSSION: The study results will help clarify the safety and efficacy of TDKL as treatment for psoriasis with respect to both disease regression and recurrence rate. We expect that this study will provide high-quality evidence with important public health implications that may alter the approach to psoriasis management in China. TRIAL REGISTRATION: The trial has been registered at ClinicalTrials.gov (ID: NCT03942198).