Anal pruritus (PA) is a common localized pruritus. It is sometimes mildly itchy in the anal region and becomes pruritus if the itching is severe and persistent. It is a common confined neurological dermatosis. It is usually limited to the perianal area, and some may spread to the perineum, vulva or the back of the scrotum. It occurs mostly in the middle and old age of 20 to 40 years old, less often in young people under 20 years old, and rarely in children. It is more common in men than in women, and this pruritus occurs more often in people who are used to quiet and infrequent exercise. Secondary pruritus has an obvious causative cause and is easily treated; spontaneous or unexplained PA is not easily cured and often recurs, accounting for about 50% of all patients. PA can be divided into primary pruritus and secondary pruritus according to the cause. 1, primary pruritus Primary pruritus is not accompanied by primary skin damage, with pruritus as the main symptom. 2, secondary pruritus Secondary pruritus arises from primary diseases and various skin diseases, accompanied by obvious specific skin damage and primary lesions, pruritus is often a symptom of the primary lesion. For example, anal pruritus caused by anal fistula, anal eczema, warts, neurodermatitis, anorectal tumors, pinworms, etc. are all in this category. Symptoms Initially, anal itching is light, with no obvious changes in anal skin, mostly paroxysmal. In patients with prolonged disease, itching is more intense and lasts longer, especially at night. Excessive scratching or mechanical stimulation makes the perianal skin hypertrophy and roughness, deepens the anal folds, local scratches, blood scabs, ooze, and residual fecal dirt in the folds, and in more severe cases, infection can be combined with pus vesicles or purulent secretions, flushing and swelling. The lesions may extend to the perineum, scrotum, female vulva and even the skin of both buttocks. Clinical examination may reveal internal hemorrhoids, external hemorrhoids, mixed hemorrhoids, anal fistula, or laboratory tests may reveal diabetes mellitus, pinworms, Candida albicans infection, etc. Treatment 1. Treat the primary disease or comorbidities such as hemorrhoids, anal fistula, pinworms, etc., and give appropriate antibiotics or antibacterial drugs to treat co-infections. 2, avoid inappropriate self-treatment, many anal pruritus patients do not want to go to the hospital, take improper self-treatment, such as scalding with hot water, external use of high concentrations of corticosteroids or containing anti-irritant drugs, the purchase of some crude home physiotherapy equipment self-treatment, these methods are harmful, only temporary suppression of itching, over time, resulting in the lesions move to increase, patients should be advised to stop using. 3, pay attention to hygiene, do not eat or eat less irritating food, such as spicy food, strong tea and coffee, strong wine, etc.. Clothing and pants should be loose fitting, close underwear to cotton fabric is good. 4, limited anal pruritus drug therapy should be based on local topical treatment, systemic treatment of various types of agents used, such as corticosteroids, anti-inflammatory mediators, a variety of sedatives and other anal pruritus does not have a significant anti-itch effect, but there are many side effects or adverse effects, in the absence of clear indications should avoid the application. 5, injection therapy, injection of drugs into the subcutaneous or intradermal, destruction of sensory nerves, so that local sensation decreases, symptoms disappear, local injury cure, about 50% of cases can be permanently cured. However, those with strict itching are prone to recurrence and need to be treated by injection again. Injected drugs not only destroy sensory nerves but also motor nerves, which often lead to sensory anal incontinence and sphincter malfunction of different severity, but can recover on their own after a period of time.