Psoriasis is a chronic, relapsing, inflammatory, systemic disease induced by a combination of genetic and environmental effects that are immune-mediated. Psoriasis vulgaris can take many forms, such as punctate, plaque, coin, map-like, and oyster shell. The initial lesions of psoriasis are often red or brown-red dots and papules with dry white scales, which gradually expand into brown-red patches with clear borders, and adjacent lesions can fuse with each other, with silvery-white scales that gradually thicken, and film phenomenon and punctate bleeding can appear when scratching, which is a typical manifestation of psoriasis. Psoriasis can be divided into progressive phase, stationary phase and regressive phase. There are various forms of common psoriasis, such as punctate, follicular, coin-like, map-like, eggshell-like, etc.