Psoriasis is more prone to recurrence and is generally predominant in winter and spring. Treatment principle: ladder treatment (i.e. treatment can be simple and effective), in the order of topical drugs (carbotriol, retinoids, nitrogen mustard, Chinese ointment, etc.), physiotherapy (medicinal bath, ultraviolet light, etc.), oral drugs (Chinese medicine, proprietary Chinese medicine, immunosuppressants of Chinese and Western medicine, hormones, etc.). Choose according to the situation. Preventive measures: good eating habits (light, nutritious diet; drink more water; eat more fruits and vegetables; avoid alcohol and spicy especially in winter and spring); pay attention to exercise to prevent colds and pharyngitis; local cleanliness and moisturizing; avoid scratching; rest well and avoid staying up late. In addition, a good state of mind is also important, timely consultation and treatment of problems, not to have a psychological burden.