The main causes of itchy wounds in patients with anal fissures include itching caused by the fissure itself and itching caused by other lesions in the body. The itching is mainly caused by the presence of many small fissures in the anal canal, which are easily stimulated by tissue fluid and bacteria and become infected, thus causing itching. Itching caused by anal fissures should be actively treated by applying erythromycin ointment to the affected area to relieve itching and reduce inflammation. When patients with anal fissures develop inflammatory lesions in other areas or systemically, some bacteria or microorganisms may also reach the anal canal through the bloodstream, causing itchiness around the anus. In addition, hemorrhoids and perianal abscesses and other anal lesions can also cause the symptoms of the swelling.