Pruritus ani can affect up to 5% of people, and is more common in men between 40 to 60 years of age. There are many causes of pruritus ani, the majority of which can be linked to a certain medical problem, such as hemorrhoids or anal fissures. Other common causes include irritation from fecal material, infections, contact dermatitis, reactions to food and clothing, medication side effects, colorectal and anal cancer, dermatologic conditions, as well as other medical and psychological conditions. The treatment of pruritus ani depends on the cause of the symptoms.
Fecal ContaminationThe skin coming into contact with fecal material, either in large or small amounts, is a common cause of pruritus ani. This may be as a result of direct irritation of the skin, or possibly as an allergic cause. People with frequent bowel movements, loose stools, and those consuming large amounts of coffee (which lowers the anal sphincter's muscle tone) may be at increased risk for fecal contamination as a cause of pruritus ani. Increasing stool consistency, such as by decreasing coffee intake, increasing bulk-forming agents, and taking medications such as loperamide (to decrease diarrhea) may improve symptoms.
InfectionsInfections of the peri-anal skin may also cause pruritus ani. These include pinworms (Enterobius vermicularis), fungal and yeast infections (such as with Candida albicans), and bacterial infections (such as with Streptococci and Staphylococci). Scotch tape tests are useful for diagnosing pinworm infection, and cultures are helpful for the diagnosis of fungal and bacterial infections. Treatment depends on the type of infection that is found.
Contact DermatitisContact dermatitis of the anal region can also result in pruritus ani. Causes include toilet paper dye and fragrances, cleansing wipes, soaps, laundry detergents, and any topical medications placed on the region in an attempt for symptom relief. Patch testing may be useful in diagnosing contact dermatitis, and treatment with topical steroids, especially those in ointment form, can be helpful.
Foods and MedicinesVarious foods are known to cause or worsen symptoms of pruritus ani, especially when those foods increase the amount of stool frequency or result in loose stools. Examples of these foods include caffeinated beverages (especially coffee and tea), alcohol, chocolate, tomato products, and -- less likely -- dairy products, nuts, spices, citrus, spicy foods, prunes and figs. Most of these reactions are not from an allergic cause, as other symptoms would be expected from food allergies, especially skin symptoms such as hives and itching over the entire body. A trial of eliminating the above foods from your diet for two weeks may be helpful to reduce symptoms of pruritus ani.
Certain medications can cause pruritus ani, including laxatives, colchicine, peppermint oil and various antibiotics. These medications cause pruritus ani not through an allergic cause, but more likely as a result of direct irritation or as a result of loose stool consistency and increased bowel movement frequency.
Colorectal/Anal Diseases and Dermatological ConditionsUnderlying medical problems of the colorectal and anal area, such as hemorrhoids, can worsen pruritus ani. Other more serious causes of pruritus ani include anal and colorectal cancers. Various skin disorders can cause pruritus ani; these include psoriasis, lichen sclerosis, and different forms of skin cancer. These conditions are often diagnosed with the help of a skin biopsy.
Miscellaneous CausesSome people with pruritus ani may be suffering from an internal medical condition, such as diabetes mellitus, liver disease, kidney disease, leukemia, lymphoma, iron deficiency anemia and hyperthyoidism. Psychological factors can also cause pruritus ani, such as anxiety and stress. Treating these underlying medical and psychological problems may help your symptoms improve.
Given the wide range of causes of pruritus ani, including some that can be dangerous, it's best to seek the advice of a healthcare professional rather than to attempt to treat this condition yourself.
Siddiqi S, Vijay V, Ward M, Mahendran R, Warren S. Pruritus Ani. Ann R Coll Surg Eng. 2008; 90:457-63.
DISCLAIMER: The information contained in this site is for educational purposes only, and should not be used as a substitute for personal care by a licensed physician. Please see your physician for diagnosis and treatment of any concerning symptoms or medical condition.