Intense itch is a common problem in skin diseases. The itch may be localized or generalized. In clinical practice, it often shows paroxysmal intense itching, burning, insect crawling and other sensations, so patients can feel the clinical manifestations of the disorder to diagnose severe itchy skin. Clinical diagnosis of severe itchy skin: 1. Systemic primary, initially confined to one place, gradually expanding to large parts of the body or the whole body. In limited cases, it occurs in a certain part of the body, and is more common in the anus, scrotum and female genitalia. 2. Without primary dermatitis, scratching can cause scratches, papules, blood crusts, hyperpigmentation, eczema-like changes and moss-like changes on the skin. 3, paroxysmal intense pruritus, pruritic episodes often have a regular feature. In addition, there are also burning, insect crawling and ants and other sensations. 4, emotional impulses, environmental temperature changes and clothing friction and other stimuli, can cause itching attacks or aggravate. Related diseases itching is usually caused by skin diseases. However, some itching is treated as a skin disease, but it is not cured for a long time. Even if it is temporarily relieved, it comes back soon afterwards. Therefore, for that long-lasting, stubborn and widespread itching, it should be considered to be caused by visceral and systemic diseases.