A Multicentre Randomized Controlled Clinical Study on the Chitosan Nanocrystalline Qinteng Huoxue Runji Ointment Therapy for Psoriasis With Blood Stasis Syndrome.

Inclusion Criteria: 1. Meets the diagnostic criteria of plaque psoriasis vulgaris; 2. Meets the diagnostic criteria of plaque psoriasis with blood stasis syndrom; 3. 18 ≤ age ≤65 , gender is not limited; 4. Quiescent patients; 5. Severity of the disease: mild to moderate lesions were 3≤PASI≤10, and 3≤BSA≤10; 6. Volunteers can understand the research content and sign the informed consent voluntarily. The informed consent process complies with the provisions of the GCP. Exclusion Criteria: 1. psoriasis induced by drug factors; Combined with non-plaque psoriasis (i.e. guttate, joint, pustule, erythroderma, or other types of psoriasis); Skin lesions were found only in special parts of the face, scalp, nails, creases, glans, mucous membranes, palms and plantar. 2. Received abiotic agents of systemic drug therapy within 4 weeks prior to randomization, including but not limited to systemic glucocorticoids, retinoids, methotrexate, and cyclosporine; 3. Received biologics within 12 weeks or 5 half-lives prior to randomization (whatever is longer), including but not limited to interleukin antibodies (e.g. Usinumab, secuchiumab, etc.) and tumor necrosis factor a antagonists (e.g. Etanercepp, infliximab, adalimumab, etc.); 4. Local topical psoriasis treatment, including retinoids, vitamin D3 derivatives, glucocorticoids, etc., had been received within 2 weeks before randomization; 5. Use of physical therapy within 4 weeks before randomization, including phototherapy (such as UVB, PUVA), phototherapy combined therapy, bath therapy, etc.; 6. systemic anti-infection therapy within 4 weeks prior to randomization; A recurrent, chronic, or active infection at baseline that the investigator determined would increase the subject's risk; 7. with a serious, progressive, or uncontrolled disease, including but not limited to past or current autoimmune disease (such as: Rheumatoid arthritis, systemic lupus erythematosus, inflammatory bowel disease, etc.) or diseases of the endocrine system, blood system, urinary system, hepatobiliary system, respiratory system, nervous system, mental system, cardiovascular system, gastrointestinal system or infectious diseases, malignant tumors; A history of drug abuse, alcohol/drug abuse; 8. Patients with serum creatinine higher than the upper limit of normal, glutamic pyruvic transaminase or glutamic oxalacetic transaminase level ≥1.5 times the upper limit of normal; 9. Patients who have participated in clinical trials and used investigational drugs within 1 month; 10. Patients who are allergic to known components of the trial intervention; 11. The patient (including the partner) has a pregnancy plan from 2 weeks before the first dose to 1 month after the last dose or is unwilling to take effective contraceptive measures during pregnancy or lactation; 12. There are circumstances that other investigators consider unsuitable for study participation, such as subjects with other skin problems that hinder the evaluation of psoriasis, potential compliance problems, inability to complete all examinations and evaluations as required by the protocol, and uncontrollable risks to study participation.