Dear Doctor: What can I do about persistent, intermittent rectal itch? I keep the area clean and dry and have tried numerous over-the-counter anti-itch medications, which seem to work for a short time before becoming ineffective. My primary care physician gave me an anti-fungal prescription (clotrimazole with betamethasone), which my dermatologist said was unwarranted. Your suggestions?
Dear Reader: Kudos to you for being willing to talk about this annoying symptom that most people don't like to acknowledge, even to their doctors. Be assured: Anal itching (pruritus ani) is a common condition affecting 1 to 5 percent of the population. It's four times more common in men than in women and occurs predominantly between the ages of 40 and 70.
As for why the condition occurs, it's generally due to small amounts of fluid stool that irritate the anal region. This may be because the stool itself is loose or because the anal sphincter is abnormally relaxed, allowing leakage. In both cases, fecal material irritates the area beyond the sphincter and causes itching, leading to excessive wiping or scratching of the region. A 1982 study found that 50 percent of people with anal itching normally had loose stools and that 41 percent lost small amounts of stool at least one day a week. Of note, coffee has been found to relax the sphincter in 70 percent of people with the condition.
Other factors can lead to pruritus ani as well, with fungal infections accounting for 15 percent of episodes. People with diabetes, those who are taking medications that suppress the immune system and those who have used multiple courses of antibiotics are at increased risk of this type of infection.
Bacterial infections can also cause anal itching. So can chemicals from soaps, creams or wet wipes, either through direct irritation or through an allergy to these products. Hemorrhoids and psoriasis can be factors too.
The first step in treating pruritus ani is to eliminate practices that irritate the anal region. Start by washing the area -- without soap -- to remove any retained material. This can be done with a bidet, or through showering or bathing. Other steps: Use softer, more absorbent toilet paper to make wiping less irritating; make sure the anal area is dry before putting on underwear; and use a zinc oxide cream to help heal the anal area and create a barrier against further irritation.
As for food and drink, not only has coffee been associated with anal itching, other foods and beverages have also been implicated. These include beer, cola, caffeinated tea, chocolate, citrus foods and drinks, tomatoes, chocolate, peanuts and grapes.
The antifungal preparation that your primary care doctor recommended includes a mixture of antifungal and steroid compounds. The steroid betamethasone eases the itching, and the clotrimazole cream acts against any existing fungal infection. However, strong steroid creams can cause skin thinning in the anal region, potentially leading to further irritation and itching.
In summary, take a hard look at the foods and drinks you're consuming; remove irritating soaps or wet wipes; use water to clean the anal area; keep the area dry; and use a zinc oxide cream to help healing. By following these strict habits, you just might be able to rid yourself of this annoying symptom.
Robert Ashley, M.D., is an internist and assistant professor of medicine at the University of California, Los Angeles.
Send your questions to email@example.com, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.