What is pruritus ani (anal itching)?
pruritus ani is a dermatological condition characterized by itching in the anal area. The itching may become worse at night or after a bowel movement. Scratching the area results in further irritation and makes the itching worse instead of relieving it. Scratching with the fingernails may result in skin damage or an infection. If the itch-scratch cycle persists, it can lead to extreme discomfort, soreness, and burning.
What are the types of pruritus ani?
There are two main types of pruritus ani—primary and secondary.
- Primary (idiopathic) pruritus ani—This condition has no identifiable underlying cause. This is the most common type of pruritus ani.
- Secondary pruritus ani—This condition may be due to many different underlying causes. They may include infections, contact dermatitis or other dermatological conditions, systemic diseases, and other factors.
How common is pruritus ani?
It is estimated that 1-5% of the population is affected. Pruritus ani is about 4 times more likely to occur in men than in women. Primary or idiopathic pruritus ani accounts for the majority (about 50-90%) of cases.
Symptoms and Causes
What can cause dryness and irritation in the anal area?
The anal area may become dry and irritated due to the use of harsh soaps, sanitary wipes, or rough toilet paper to clean the area after a bowel movement. A hypersensitivity reaction may occur if perfumed powders, lotions, creams, ointments, or other products are applied in the anal region. Excess perspiration or small amounts of fecal matter can cause irritation and itching.
What causes pruritus ani (anal itching)?
Pruritus ani is usually not caused by poor hygiene. Rather, the overuse of soaps and other topical products to clean the anal region or vigorous scrubbing with a washcloth or rough toilet paper can cause irritation. A hypersensitivity reaction may occur if perfumed powders, lotions, creams, ointments, or other products are applied in the anal region.
Excess perspiration or moisture may become trapped in the anal area if constricting or tight-fitting underwear is worn. Some foods and beverages, such as carbonated drinks, caffeinated beverages (coffee, tea, colas) and spicy or acidic foods (tomatoes, citrus fruits) have been linked to the condition. Having frequent bowel movements (diarrhea) or infrequent ones (constipation) may also play a role.
Other causes of pruritus ani include:
- Infections: Some types of bacteria, fungi (yeast), or parasites can cause itching. Staphylococcus aureus or Streptococcus pyogenes (types of bacteria), Candida albicans (a yeast), pinworms (mainly in children), and Sarcoptes scabiei (scabies mites) are some organisms that result in itching and irritation.
- Dermatological conditions: Psoriasis, contact dermatitis (inflammation due to allergens or other irritants), or atopic dermatitis (a chronic condition found in patients with allergies) may cause a rash in the perianal region.
- Inflammatory bowel disease (Crohn’s disease)
- Psychological factors such as stress or anxiety
- Systemic diseases: These include diabetes mellitus, leukemia, lymphoma, thyroid disease, renal disease, and liver disorders (obstructive jaundice).
- Colorectal and anal disorders: Rectal prolapse, internal or external hemorrhoids, anal fissures (ulcers), or fistulas (abnormal tube-like passages) are associated with pruritus ani. Residual amounts of feces may be difficult to remove with large external hemorrhoids. Internal hemorrhoids may cause bleeding, fecal soiling, or drainage.
- Systemic or topical medications: Use of drugs such as quinine, colchicine, and mineral oil has been linked to pruritus ani.
- Fecal or urinary incontinence: Children and the elderly are more likely to experience incontinence of the bowel or bladder.
Diagnosis and Tests
How is pruritus ani (anal itching) diagnosed?
The doctor will obtain a full medical history and perform a physical examination to identify possible underlying causes, such as dermatological conditions and other illnesses. He or she will visually inspect the area to look for changes in skin color or texture, rashes, or lesions. The doctor will ask about any medications that you take and the type and frequency of bowel movements.
The doctor may obtain skin specimens and perform tests to screen for bacterial or other infections.
Parents of children who may have pinworms can place a small piece of surgical tape, or scotch tape, near the child’s anus before bedtime. The worms are more likely to emerge at night. In the morning, when the child awakens, the tape can be removed to see if the worms or their eggs are present. This is called the scotch tape test.
Management and Treatment
How is pruritus ani (anal itching) treated?
Usually, treatment focuses on establishing and maintaining a routine for proper anal hygiene. If a secondary or underlying cause is found, the treatment will depend on the specific condition.
- Topical medications: Topical steroids, such as creams or ointments containing 1% hydrocortisone, may help to relieve itching and irritation. The cream or ointment may be applied two or three times to the affected area each day. Topical capsaicin has been studied as an alternative to steroids for patients with chronic pruritus ani.
- Oral medications: Antibiotic or antifungal medications may be prescribed if an infection is present.
- Methylene blue injection (anal tattooing): This technique may be used to treat more advanced cases that do not respond to topical medications. Methylene blue (a dye) is injected under the skin in the perianal region. It is thought that the methylene blue relieves pain and itching by deadening the nerve endings where the dye is injected.
What are some tips for self-care?
- Resist the urge to scratch. The itching might seem worse at night, so people might unconsciously scratch the anal area with their fingernails during sleep. Wear clean, soft cotton gloves at bedtime to prevent irritation and infection.
- Keep the perianal area clean and dry. Use clear water instead of soap or moistened toilet paper to clean the perianal region after a bowel movement. A shower head or bidet may be used to gently clean the perianal area. Use a hair dryer on a low setting to dry the area. If using toilet paper or a towel, gently pat or blot the area until it is dry.
- Apply a small amount of cornstarch or piece of cotton to the area to keep it dry during the day. A small cotton gauze pad can be used instead.
- Do not use soap when cleansing the anal area or scrub vigorously with toilet paper or a washcloth.
- Avoid using perfumed creams, lotions, bubble baths, powders, or other products that may cause irritation to the area.
- Eat foods high in fiber. A healthy diet can help prevent diarrhea or constipation and ensure regular bowel movements. Avoid any foods that might promote itching, such spicy or acidic foods or caffeinated beverages.
- Avoid wearing tight or constricting underwear. Cotton underwear can help to absorb moisture better than synthetic fabrics. Make sure underwear fits properly and change it frequently. Wash clothing with fragrance-free detergents.
- Use topical medications as directed. Apply the cream or ointment sparingly and discontinue use if the itching does not subside or gets worse.