What is the performance of pruritus and how to diagnose?

According to the scope of itching, the disease is divided into systemic or limited.
1. systemic pruritus (pruritus universalis) patients all over the body are itchy feeling, but not the body at the same time itchy, often moved from one place to another. The degree of itching is not the same, although some people feel itchy skin, but still can endure, and some patients feel itchy body, need to use iron brush brush skin or hot water wash until the skin bleeding and feel pain and burning, Itchy mind temporarily reduced. Often with itchy at night, the patient because of itching and insomnia or can not sleep. Due to severe itching, and constantly scratching, there may be scratches, blood scab, or strip of scratches, sometimes eczema-like changes, moss-like change or pigmentation. Scratched skin is also susceptible to infection and boil or folliculitis.

Elderly pruritus occurs in the elderly are often the most itchy trunk; winter pruritus appears in the cold season, due to cold induced, the patient often get out of sleep, began to feel the anterolateral medial side, calf and other parts of the severe itching, , And the more itchy grasping, until the local bleeding so far.
2. limitations of pruritus clinical more common in the anus, female and scrotum and other parts
(1) anal pruritus is the most common localized pruritus, more common in middle-aged men, often confined to the anus around, and sometimes spread to the scrotum forward, back to the gluteal groove on both sides, women can also disease, children suffering from pin Insects can also cause anal pruritus. Anus around the skin often pale or pale white dipping, anal folds hypertrophy, due to scratch and radial chapped; sometimes secondary infection; prolonged skin around the anus thickening, and become moss, can also occur pigment calm.
(2) female Yin itching occurs mainly in the labia majora and labia minora, Yin Fu and clitoris can also occur, because itching often scratching, vulvar skin hypertrophy, was gray and white impregnated, clitoris and vaginal mucosa swelling and erosion.
(3) scrotum itching itching occurs in the scrotum, but also can affect the penis or anus. Due to continuous scratching, scrotal skin hypertrophy, and pigment changes, or moss-like change, and some patients can see erosion, exudation and scab and eczema-like changes.