Itching in the anus, can be seen in hemorrhoids = hemorrhoids, anal fistula, parasitic disease, rectal prolapse or perianal eczema and many other diseases. 1. Hemorrhoids: If external hemorrhoids occur, there is anal impurity and moisture, can cause itching symptoms, if there is acute thrombosis, there can be severe anal pain. 2. anal fistula: mostly from the rectal perianal abscess rupture or incision and drainage in the perianal skin to form an external port, can be intermittent or continuous flow of blood, pus or mucous secretion, anal skin can be due to the stimulation of secretion, there is wet skin itching. 3. Parasitic diseases: If pinworm disease occurs, especially at night, the worm crawls out of the anus to lay eggs, which can make the skin of the anus intensely itchy, and children can have night terrors. 4. Rectal prolapse: partial or total displacement of the rectal wall, when the prolapse gradually aggravated, can cause varying degrees of anal incontinence, mucus outflow, can make the anus and perianal skin itching or cause eczema. 5. Eczema: perianal, vulva or scrotum and other places of eczema can have localized intense itching, can be caused by scratching redness, swelling, oozing or erosion, which can be chronic. Itchy skin around the anus and the mouth, we should go to the hospital specialist in time, after a clear diagnosis, the cause of the symptomatic treatment to avoid aggravation of the condition, and pay attention to keep the perianal area clean and dry.