Background: Hyperplastic disease of the breast (HDB) is caused by a hormone imbalance experienced among women at a certain age. Slight breast pain is common in women before menstruation without need of treatment; however, if the pain becomes severe, it can cause physical and mental suffering. Therefore, it is of great clinical significance to control this disease.
Methods and design: This study will follow the principle of evidence-based medicine and adopt various design methods, being conducted as a randomized, controlled, double-blind and multicenter trial based on the cause of HDB defined in Chinese and Western medicine. According to the cause of HDB in Chinese and Western medicine and its pathogenesis and prognosis, this study will conduct syndrome differentiation, adopt external therapy of Chinese medicine by using Sanjie Zhitong plaster as the intervention, take placebo as the control method and aim at relieving pain. The effectiveness and safety of Chinese medicine therapy will be evaluated. During the design process, some confounding factors will be taken into consideration and prevented with corresponding measures. We will also discuss the side effects of the medicine used and corresponding countermeasures to be taken.
Discussion: On the basis of traditional Chinese medicine (TCM) theory, Sanjie Zhitong plaster takes the advantage of external therapy of TCM. According to the main etiology and pathogenesis of HDB, the treatment principles of warming the meridians and activating blood, smoothing circulation and relieving pain, and removing swelling and dissipating stagnation are put forward. The medicine exerts its effects directly on the lesion site by permeating into the skin and stimulating the meridians, thus improving blood supply to the breast and relieving pain.
Trial registration: ChiCTR-TRC-11001297.

Key words: external therapies, fibrocystic breast disease, randomized controlled trial, clinical protocols