Anal Itching (Pruritus Ani)

What is anal itching?

Anal itching is the irritation of the skin at the exit of the rectum, known as the anus, accompanied by the desire to scratch. Although itching may be a reaction to chemicals in the stool, it often implies that there is inflammation of the anal area. The intensity of anal itching and the amount of inflammation increases from the direct trauma of scratching and the presence of moisture. At its most intense, anal itching causes intolerable discomfort that often is described as burning and soreness.

What causes anal itching?

• Anal itching can be caused by irritating chemicals in the foods we eat, such as are found in spices, hot sauces, and peppers.
• Anal itching also can be caused by the irritation of continuous moisture in the anus caused by frequent liquid stools, diarrhea, or escape of small amounts of stool (incontinence). Moisture increases the possibility of infections of the anus, especially yeast, particularly in patients with diabetes mellitus or HIV.
• Treatment with antibiotics also can lead to a yeast infection and irritation of the anus.
• Psoriasis also can irritate the anus.
• Abnormal passageways (fistulas) from the small intestine or colon to the skin surrounding the anus can form as a result of disease (such as Crohn's disease), and these fistulas bring irritating fluids to the anal area.

Other problems that can cause anal itching include:

• pinworms,
• hemorrhoids,
• tears of the anal skin (fissures), and
• skin tags (abnormal local growth of anal skin).