Our Choice: study protocol for a randomized controlled trial for optimal implementation of psoriasis treatment by the integration of Chinese and western medicine.

Background: Plaque psoriasis is a refractory inflammatory skin disease. The common therapies used to treat plaque psoriasis in traditional Chinese medicine (TCM) and western medicine (WM) have distinct characteristics and advantages. Although a combination of TCM and WM therapies, adjusted to the clinical situation, is widely used, there are no systematic studies on the hierarchical selection of this treatment combination based on the severity of skin lesions. We therefore designed a randomized clinical trial to focus on the sequence of internal and external treatments of TCM in patients with mild-to-moderate plaque psoriasis and to optimize the integration of Chinese and western medicine for the treatment of patients with severe plaque psoriasis, thereby achieving high-level clinical evidence and establish treatment norms for the integrated use of Chinese and western medicines.

Methods: In this proposed multicenter, single-blinded, randomized controlled trial, 108 patients with mild-to-moderate plaque psoriasis will be randomly assigned to two groups in a 1:1 ratio to receive either internal or external TCM treatment, and 270 patients with severe plaque psoriasis will be randomly assigned to three groups in a 1:1:1 ratio to receive treatment with TCM or WM, or TCM + WM. All enrolled patients will receive 8 weeks of treatment. Follow-up assessments will be done 8 weeks after the treatment. The primary outcome of this study is the evaluation of efficacy and relapse rate, based on the Psoriasis Area and Severity Index, and the secondary outcome measures include determination of the affected body surface area, physician's global assessment, pruritus scores (determined using a visual analog scale), TCM symptom score, Dermatology Life Quality Index, patient-reported quality of life score and incidence of serious adverse events.

Discussion: This study will provide high-level clinical evidence for internal and external TCM treatment optimization and will contribute to establishing norms for the integration of Chinese and western Medicines.

Trial Registration: ClinicalTrials.gov, NCT03941431. Registered on 8 May 2019.