Pruritus is an unpleasant sensation of the skin or mucous membranes that causes the desire to scratch. When a patient has symptoms of itchy skin and it is especially bad at night, it may be due to allergic skin disease, animal skin disease, pruritic skin disease, and other causes. 1. Allergic skin disease. Urticaria, commonly known as rubella, is a temporary increase in vascular permeability that occurs when the skin mucosa is exposed to allergens, resulting in limited edema on the skin. The clinical manifestations are red bumps of varying sizes visible on the skin of the whole body, often accompanied by intense itching, and aggravated at night. 2. Animal skin disease. In the hot summer, if the screen is not closed at night, the toxic hairs or venom of insects such as caterpillars or cryptomeria may enter the skin, causing pruritic and inflammatory dermatoses. 3, pruritic skin disease. Systemic pruritus is mainly due to dry skin and is the main symptom or manifestation of many skin diseases, certain systemic diseases nerve damage and mental diseases. Pruritus can be caused by exogenous factors (such as mechanical, electrical, thermal, cold and chemical stimulation, etc.) or endogenous factors (such as a variety of diseases, etc.); inflammation, degenerative changes, malignant tumors, psychological abnormalities and many other pathological processes can lead to the occurrence of pruritus. Some patients are prone to mental agitation and excessive thinking at night, which is more likely to cause pruritus. Therefore, if you experience itchy skin at night, please consult a dermatologist promptly and follow medical advice.