Behind the anus itch, first consider whether there is eczema manifestations, localized visible red rash, scratching with the hand after the itching symptoms worsened, there may be skin breakage, pain. In this case, try to go to the regular hospital dermatology consultation, after diagnosis, topical medication, usually pay attention to keep the local hygiene, dry. Localized skin allergies can also appear itchy discomfort, this consideration of contact allergy, such as replacement of new underwear. Also need to go to the dermatology department to confirm the diagnosis, oral anti-allergy drug treatment. If the external hemorrhoids around the anus can also be seen in the external hemorrhoids, can cause itching discomfort, due to perianal varicose blood vessels, poor blood circulation in the skin mucosa, malnutrition caused by abnormal sensation, usually do not sit for a long time, treatment to improve the symptoms of constipation, warm water bath symptoms can be gradually relieved. The parasites such as pinworms in the anus infection, can also appear local itching symptoms, mostly in children, night itching symptoms aggravated, need to take oral insecticidal drugs treatment.