Psoriasis, commonly known as “psoriasis”, is a common, easily recurring chronic inflammatory skin disease characterized by red papules or plaques covered with multiple layers of silvery white scales. It is more common in young adults than in women, and is more common in the north than in the south, and is more likely to develop or worsen in spring and winter, and to remit in summer and fall. The etiology and pathogenesis of the disease are not completely clear, but research has found that the onset of the disease is related to genetic factors, streptococcal infection, abnormal immune function and metabolic disorders and endocrine changes. There are four clinical types: the common type, the pustular erythrodermic type and the arthritic type. Psoriasis vulgaris is the most common, and the disease is chronic in nature and is prone to recurrence after cure.