There are many causes of anal itching: 1. physical condition that is related to the person. Some people’s skin is prone to allergies, and contact with chemical fiber clothing, toiletries, drugs and other substances may cause local skin itching. 2, anal infection. Fungal infections, such as foot washing and bidet mixing in patients with foot disease, can cause anal fungal infections, which can cause itching, and generally itching will increase at 8-9 o’clock. 3, anal dermatitis. Eczema is the cause of itching around the anus and rectum. 4, pinworms. Rarely, itching in the anus for a long time in the past, especially at night, is caused by parasites such as pinworms. Because pinworms crawl out at night and stay at the anus to oviposit at the edge of the anus, they cause severe itching in the anal area at night, but now with improved health conditions and increased health awareness, pinworms are very rare.