At night, perianal itching is considered to be related to perianal eczema, intestinal parasitosis, hemorrhoids and other causes. 1. Perianal eczema: the most common clinical cause. When perianal eczema occurs, it usually leads to perianal itching symptoms are more intense, itching especially at night more obvious. If you repeatedly scratch the itchy place, it will repeatedly damage the perianal skin, which will lead to thickening and mossy change of the perianal skin. 2. Intestinal parasites: pinworms are the most common. These intestinal parasites will crawl to the anal opening at night to move and lay eggs, which will lead to the emergence of obvious itching symptoms in the perianal area at night. 3. Hemorrhoids: easily lead to the formation of perianal venous thrombosis or lumps. Especially when the occurrence of internal hemorrhoids, in addition to hemorrhoids will lead to prolapse, will also bring the intestinal fluid out of the anus, so that it stimulates the skin around the anus, triggering perianal itching symptoms. When there is an itchy perianal area at night, it is recommended to pay attention to keep the anal area clean and hygienic, you can wash the perianal area with lukewarm water after the bowel movement, to avoid residual feces to stimulate the skin around the anus, which aggravates the itchy symptom. If the symptoms are serious, it is recommended to go to the hospital, clear the cause of the disease, under the guidance of the doctor for targeted treatment, to avoid aggravation of the condition.