Anal itch (pruritus ani)

What is it?

Anal itch, also known as pruritus ani, is an irritating, itchy sensation around the anus (the opening through which stool passes out of the body). Anal itch is a symptom, not an illness, and it can have many different causes. In most cases, a person with anal itch does not have a disease of the anus or rectum. Instead, the itchy sensation is a sign that one or more of the following has irritated the skin in the area:

• Stool on the skin around the anal opening — If the anal area isn't cleaned properly after a bowel movement, a small amount of stool may be left behind on the skin, causing the area to itch. Less often, watery stools may leak out of the anal opening and cause itching. This sometimes happens in otherwise healthy people whose diets include very large amounts of liquids.
• A diet containing foods or beverages that irritate the anus — A number of foods and drinks can irritate the anus, including  spices and spicy foods, coffee (both caffeinated and decaffeinated), tea, cola, milk, alcoholic beverages (especially beer and wine), chocolate, citrus fruits, vitamin C tablets, and tomatoes. Once a person eats or drinks something that can irritate the anus, it usually takes 24 to 36 hours before anal itching begins. That's the time it takes the food to travel through the digestive tract.
• Treatment with antibiotics — Some powerful antibiotics that work against many different bacterial species can trigger anal itch by disturbing the normal ecology of the intestines. These drugs are called broad-spectrum antibiotics, and include tetracyclines and erythromycin (both sold under several brand names).
• A local chemical irritation or skin allergy in the anal area — In sensitive people, chemicals and medications that are applied to the anal area can cause local irritation or allergic reactions. Some major culprits include dyes and perfumes used in toilet paper (especially scented toilet paper), feminine hygiene sprays and other deodorants for the area around the anus or genitals, medicated talcum powders, and medicated skin cleansers and soaps, especially perfumed soaps. Anal itch also can be triggered by over-the-counter medications (suppositories, creams, ointments) intended to treat anal problems.
• Intense cleaning after a bowel movement — Although the anal area should be cleaned after every bowel movement, this cleaning must be gentle. Aggressive rubbing and scrubbing, especially with soaps or other skin cleansers, can irritate the skin and trigger anal itch.

Less often, anal itch is a symptom of some illness or condition that either affects the anal area alone, or involves larger areas of the digestive tract or skin. Some examples include:

• Local diseases and conditions involving lower portions of the digestive tract — These include hemorrhoids, skin tags, rectal fistulas, rectal fissures, and, rarely, anorectal cancer.
• Infections and parasites — These include pinworms (especially in children), scabies, pediculosis, condyloma acuminata, and skin infections due to Candida or tinea fungi.
• Skin problems — These include psoriasis, eczema, and seborrhea. In many cases, these conditions cause symptoms in several different areas of the skin surface, not only around the anus.

Worldwide, anal itch is a very common problem that occurs in up to 45% of people at some time during their lives. Men are affected two to four times more often than women. People who are overweight, perspire heavily, or routinely wear tight-fitting underwear or hosiery are more likely to get anal itch.

Symptoms

Anal itch is an irritating sensation around the anus that is relieved temporarily by scratching or rubbing. The problem is often worse at night and may interfere with sleep. In most cases, the skin in the area is red.

If anal itch becomes a chronic (long-term) problem, the skin around the anus may become raw and tender from repeated scratching, or it may thicken and become leathery. Repeated scratching also can cause breaks in the anal skin that can lead to painful local infections.

Diagnosis

To help identify the cause of your anal itch, the doctor may ask you to describe your current diet and medications, your bowel habits, and the way you routinely clean your anal area after a bowel movement. The doctor will review your medical history, including any history of rectal problems (hemorrhoids, fissures, or fistulas) or skin problems (psoriasis, eczema, or seborrhea). Your doctor's questions will be followed by a physical examination of your anal area and, sometimes, by a digital rectal examination. If you have a history of skin symptoms involving other parts of your body, your doctor will want to examine these skin areas as well.

If your anal itch is due to a local irritation in the anal area, the doctor usually can diagnose the problem based on your history, diet, and personal hygiene routine, and the results of your physical examination. Sometimes, the doctor will request a stool sample if he or she suspects a worm or parasite infection. Rarely, your doctor may need to examine the area by inserting a special viewing instrument called an anoscope into your anus. This can help your doctor determine whether the itch is being caused by a problem inside your rectum.

Expected duration

How long an anal itch lasts depends on its cause. If the itch is due to a simple skin irritation, the problem usually goes away quickly once you identify the source of irritation and avoid it. In most cases, simple treatment measures provide some relief within one week and cure the problem totally within one month.

Prevention

In many cases, you can prevent anal itch by taking the following steps:

• Practice good anal hygiene. When possible, gently cleanse the anal area after every bowel movement by using wet toilet paper (unscented and dye-free) or a wet washcloth. Wipe gently or blot the area. Never rub or scrub. If you are in a public toilet, use dry toilet paper temporarily, then finish your cleansing regimen when you return home.
• Use only water to clean the anal area, never soap.
• Avoid using medicated powders, perfumed sprays, or deodorants on the anal area.
• Eat a sensible diet that is low in the foods and beverages known to cause anal irritation.
• Wear cotton underwear that is not too tight.
• If you are taking oral antibiotics, eat yogurt to help restore the normal ecology of your colon.

Treatment

In most cases, anal itch can be treated by:

• Thoroughly but gently drying the anal area after every bowel movement, using unscented toilet paper, a clean cloth towel, or a hair dryer if necessary.
• Dusting the anal area with nonmedicated talcum powder between bowel movements, or laying a clean square of cotton gauze against the anus to absorb any excess moisture.
• Resisting the urge to scratch, no matter how itchy the area becomes. The itch will pass, or at least decrease in intensity, over a short time, but the more you scratch, the longer it will take for the itching to go away.
• Applying topical remedies such as zinc oxide or hydrocortisone ointment (1%) on a regular schedule, or as needed, to help you avoid scratching.
• Wearing soft cotton gloves while in bed if you scratch at night or in your sleep.

When to call a professional

If treating anal itch yourself doesn't relieve the itch after three to four weeks, call your doctor.

Prognosis

The outlook is excellent, since most people who have itching in the anal area don't have an illness involving the anus or rectum. Overall, about 90% of patients find relief by avoiding scratching and other simple therapies.

Additional info

National Institute of Diabetes and Digestive and Kidney Disorders
https://www.niddk.nih.gov/

American Gastroenterological Association
https://www.gastro.org/