Anal pruritus is a common localized pruritus and limited neurological dysfunctional skin disease. Both men and women, young and old, are susceptible, with a prevalence of up to about 3% in the population, with men and older people being more common and quiet and less active. Anal pruritus can be divided into two categories: idiopathic and secondary. Idiopathic anal itching is the itching that has no cause to be found, this idiopathic anal itching, not many, most of the anal itching is secondary, that is, the itching caused by disease. If the cause can be removed, the treatment will be very good. The common possible causes of anal itching are analyzed as follows: 1, perianal neurodermatitis: characterized by intense itching, sudden onset, intense itching. Commonly seen in people with tension, anxiety, and low self-esteem complexes. The main manifestation is that the local skin appears polygonal and fused together with papules, scratching due to itching often makes the lesions thicken, mossy as bark-like. 2. Perianal fungal infection: Especially in hot and humid seasons, elderly people who are obese and sweaty are prone to skin fungal infection and ringworm, which often causes perianal itching due to the expansion of the lesions to the vicinity of the anus. The main manifestation is an annular or semi-annular or map-like erythema with clear borders on the inner thighs or buttocks, with a layer of white phosphoric flakes on the surface. When scraping off its phosphorous flakes under the microscope, fungal mycelium and spores can be found. 3, perianal viral infection: suffering from anal condyloma acuminata or infectious molluscum contagiosum can also cause anal itching. The former is mainly manifested around the anus to appear cauliflower-like or like a cocklebur-like wart-like growths, moist and filthy and foul-smelling; the latter skin lesion morphology is round or hemispherical wart-like growths, the center has a “navel”-like depression, the occurrence of the site in addition to the perianal, scrotum, but also spread to the whole body skin. 4, perianal parasitic infection: generally seen in children, but adults can also be infected and the most common night itching. At night, when the anus is relaxed, pinworms often crawl out of the rectum and lay eggs and mate around the anus, causing anal itching due to stimulation of the perianal skin and characterized by night itching. When suffering from scabies, if the skin damage of the vulva spreads to the vicinity of the anus, it can also cause anal itching. In addition, the stimulation of leukorrhea when suffering from trichomonas vaginalis in old age can also cause anal itching. 5, perianal eczema: mainly manifested as a circle of perianal papules, blisters, and even erosion and oozing skin damage, often due to intense itching, repeated scratching and cause thickening of the skin around the anus, mossy, the appearance of most become gray-white. 6, perianal psoriasis: perianal psoriasis can also cause severe itching, and the general damage is clearly defined, with psoriatic rashes visible in other parts of the body. 7, perianal seborrheic dermatitis: In addition to the anus, there can be similar rashes in other parts of the body such as the groin. 8, perianal contact dermatitis: common in the contents of the stomach and intestines, perianal feces or secretions stimulation; wearing underwear (such as dyes, nylon, etc.) and hand paper friction stimulation can lead to the onset. 9, due to anal diseases: such as anal fissure, anal fistula, hemorrhoids, rectal prolapse, anal incontinence, etc., so that the anal opening secretions increase, damp stimulation of the skin caused by itching. 10, due to systemic diseases: anal itching caused by systemic diseases is not uncommon, such as lymphoma, diabetes, vitamin A and D deficiency, etc.. Liver and kidney diseases such as primary biliary cirrhosis or biliary obstruction patients, due to increased blood and skin bile salt content, stimulation of nerve endings resulting in itching; renal disease late uremia can also occur anal itching. 11, due to other factors: allergic reactions such as the consumption of irritating food, such as chili, wine, etc.; or neurasthenia, excessive mental tension, excitement, excitement and other mental factors cause nerve dysfunction, can also trigger or lead to itching. Anal itching countermeasures 1, develop good hygiene habits: wash your hands before meals, bathe regularly, change your clothes and pants regularly, underwear should be wide soft texture, comfortable, try to avoid wearing artificial fiber woven underwear. 2, keep the anal local clean: after the stool or before bedtime should be used to wash the anus with warm water bath; but pay attention not to use too hot water, generally do not need to use soap, especially do not use alkaline too heavy soap. 3, timely treatment of systemic and local primary lesions that may cause anal itching. 4, regulate the diet: diet should be light and easy to digest, spicy and thick products and tobacco and alcohol should be avoided. Eat less fish and shrimp, crabs, pupae, cilantro, pork and other things that are prone to wind rash, eat more fresh vegetables and fruits. 5, perianal itching should not be scratched with hands, can be applied externally anti-itch cream or hormone ointment, such as fluorescein acetate ointment, etc., night itching affect sleep, can be taken orally before bedtime a piece of fenagin or cyproheptadine. 6, can be combined with Chinese medicine sitz bath. 7.Surgical treatment.