Pitting of the finger (toe) nail is a symptom of psoriasis involving the nail. Psoriasis of the nail matrix area will show pitting of the nail plate, ridges and grooves, while nail peeling, hyperkeratosis under the nail and ruptured bleeding. Psoriasis, commonly known as psoriasis, is a chronic inflammatory skin disease with a long course, a tendency to recur, and in some cases, almost lifelong. The onset of the disease is predominantly in young adults and has a greater impact on the physical health and mental status of the patient. The clinical manifestations are mainly erythema and scaling, which can develop all over the body, with scalp and extremities being more common, and mostly aggravated in winter. Psoriasis vulgaris is the most common type in clinical practice. The surface is covered with silvery white scales, and the smooth film is revealed after gently scraping off the scales, and multiple tiny bleeding dots can appear after scraping again. The above-mentioned scales, film and bleeding are the three main clinical features of the disease. The disease can occur on any part of the body and is symmetrically distributed, usually on the knee, elbow joint extension and head. Pustular psoriasis is divided into two types: generalized and restricted: 1. Generalized pustular psoriasis is rare clinically. The onset of this type is rapid, with general discomfort and systemic symptoms such as flaccid hyperthermia and leukocytosis. The lesions are initially acute inflammatory erythematous plaques, with most dense pinhead to corn size yellow-white sterile shallow small pustules on the surface. The pustules may expand and fuse to form a “pus paste”. It often involves a wide range of skin surface and can even extend to the whole body. The causes of the disease are mostly related to the onset of psoriasis vulgaris after long-term use of corticosteroids and sudden discontinuation of the drug, or to infection or drug stimulation. The disease is heavy, often recurring periodically, and the prognosis is poor. 2, limited pustular psoriasis, also known as palmoplantar pustular psoriasis, mostly confined to the palmoplantar, often occurring in batches in the size of the fissure or the foot plantar area, most yellowish pinhead to corn size pustules, the base flushed. After about 1 to 2 weeks, the pustules rupture, crust and flake off. Later, small pustules appear under the scales, sometimes light and sometimes heavy. Self-perceived itching or pain. The nails may be involved and are cloudy and hypertrophic, with crestal elevations. Psoriatic lesions are often seen on other parts of the body. There are also cases where the lesions first appear in the palmoplantar area and then become generalized after repeated attacks.