Abstract: 【Abstract】 Psoriasis is an immune-mediated chronic, recurrent, inflammatory, systemic disease induced by the combination of heredity and environment. Psoriasis is a non-communicable disease, its typical clinical manifestations are limited or widely distributed scaly erythema or plaques. Its treatment is very difficult, and patients need lifelong treatment. The etiology of psoriasis involves heredity, immunity, environment and other factors, and may be considered as excessive proliferation of keratinocytes or inflammation of joint synovial cells and chondrocytes caused by the immune response mainly mediated by T lymphocytes and various immune cells. In the theory of traditional Chinese medicine （TCM）, it is believed that psoriasis is mostly caused by hot toxic blood, loss of nutritional ingredient in blood, blood perfusion stasis, dry wicked wind in the body and skin system imbalance. Treatment protocols of psoriasis should be based on patient′s symptoms. Patients with mild psoriasis can be mainly treated with externally applied agents, those with moderate to severe psoriasis can be treated with systemic medications, and targeted biological agents can be appropriately chosen in those resistant to traditional systemic treatment. The main aim of psoriasis treatment is to control symptoms and improve the quality of life. Compared with the previous two editions of guidelines for diagnosis and treatment of psoriasis in China, some contents are supplemented and revised in this edition, which will further facilitate standardization of diagnosis and treatment of psoriasis in China, increase the efficiency of diagnosis and treatment, and improve the quality of life of patients.

Key words: Psoriasis, Guidelines, Diagnosis, Therapy