Can cause anal itching for very many reasons, seen in a variety of internal and external factors stimulation, in addition to skin diseases, diet, clothing, drugs and other factors can also cause itching of the liver. In addition, there are also some anal itching secondary to certain diseases, such as skin diseases, anal diseases, as well as urethral, vaginal and prostate diseases: 1. Dietary factors: fish, shrimp, crab, as well as soybeans, mangoes, etc. may cause allergic reactions in people with idiosyncratic constitutions, which can produce itching of the skin, including perianal discomfort. Consumption of spicy and stimulating foods, such as chili, mustard, etc., the products of digestion through the digestive tract can stimulate the rectal mucosa and anal skin, causing itching. In addition, some people drinking alcohol can also appear after the symptoms of anal itching; 2, clothing factors: underwear size or poor material, friction local skin or sweat can not be emitted; 3, drug factors: such as morphine, oral contraceptives and some antibiotics, etc., can cause anal, perineal skin itching; 4, skin diseases: such as anal folliculitis, eczema, warts, ringworm and other lesions, or mites, pubic lice, trichomonas and other parasitic infections. The itching of the anus is often caused by parasitic infections such as mites, lice and trichomonas. In addition, children infected with roundworms, pinworms and other intestinal parasites can also produce anal itching; 5, anal diseases: including anal fissure, anal fistula, rectal prolapse, proctitis, rectal adenoma, and even rectal cancer, may lead to anal itching; 6, urethra, vagina, prostate disease: including urethritis, vaginitis, prostatitis, inflammatory factors stimulate the skin, mucous membrane, etc. can often have itching performance; 7, other. Such as diabetes, hyperthyroidism, biliary obstruction, iron deficiency anemia, Hodgkin’s lymphoma, as well as anxiety disorders, neurasthenia and other psychiatric diseases, may show varying degrees of anal itching, which should be combined with specific clinical manifestations and relevant examinations to help determine the cause.