Anal itching – Pruritus

What is anal itching?

Anal itching is characterized by an uncontrolled urge to scratch around the anus and anal rim.

• In the vast majority of cases, the cause is benign.
• 1-5% of the population suffers from anal itching.
• Men are affected more often than women. Symptoms are most common between the ages of 40 and 60.

(Hanno R et all Classification and management  Clin 1987;5:811)
(Daniel GL Causes and concerns. Dis Colon Rectum 1994;37:670)

In about 50% of cases, no clear cause can be found for anal itching (idiopathic anal itching). Most likely, a chronic irritation is caused by contamination with fecal debris, combined with trauma due to excessive hygiene (rubbing) and scratching.

Other causes

• Irritation from loose stools and diarrhea
• Infection with “small worms” (Enterobius Vermiculairs). Itching often in children especially at night.
• Food that irritates the anus:

– Coffee, tea, beer, soft drinks

– Chocolate

– Tomatoes

– Sour /acid fruits, orange, grapefruit

• Skin diseases:

– Psoriasis

– Dermatitis: Irritation/allergic reaction of the skin after using certain soaps, ointments, detergents…

– Mycoses (fungus).

• Chronic dirt loss from an anal fistula tract (a duct that communicates between the glands around the anal canal and the skin of the anal rim).
• Internal hemorrhoids that bulge out of the anal canal when resting or defecating. The anus is then unable to close completely and dirty fluid may seep out and irritate the skin of the anal rim.
• Anal incontinence: Irritation due to chronic fluid loss.
• Sexually transmitted diseases: Condyloma, Chlamydia, gonorrhea, Syphilis and Candida.
• Very rarely, itching will occur due to cancer of the anal canal.
• A skin tag, a bulge of excess skin around the anus, is rarely a cause of itching.
• (Jensen SL et al  A randomised trial of simple excision of non-specific hypertrophie anal papille versus expectant management  in patients  with chronic pruritus ani.

(Jensen SL et al A randomized trial of simple excision of non-specific anal papilla hypertrophy versus expectant management in patients with chronic pruritus ani. Ann R Coll Surg Engl 1988; 70: 348)

Initially rule out any pathology (skin disease, hemorrhoids, etc.) that could be the cause of the itching.

What are the conservative treatments for anal pruritus?

In about 50% of cases, no pathology can be diagnosed, we then speak of idiopathic pruritus.

In 90% of cases, symptoms can be treated conservatively, after the patient has been reassured.

(Smith LE. Prospective  studies on the etiology  and treatment of pruritus ani. Dis Colon Rectum 1982;25:358)

Scratching the anus leads to scratch lesions that cause skin irritations. These lesions cause an inflammatory reaction which in turn stimulate the nerve endings. The stimulation of the nerve endings maintains the urge to scratch.  This creates a vicious cycle where chronic itching is present even though the initial cause of itching has already disappeared. This also explains why the origin of anal itching can only be determined in half the cases.

1. Hygiene: “Keep the anal region clean and dry”

Discontinue all previous treatments and other hygiene products.

Anal hygiene up to twice a day and after each defecation, preferably with water only or with non-irritating products whose pH (acidity) is adapted to the physiological pH of the skin (surgras soap such as Septiane surgras liquide® or Atoderm moussant®, dermatological soaps such as Aderma® with oat milk or Nioléol® bar, Saforelle®, Gyn-hydralin®, Marseilles soap, others…)

Twice daily sitting baths with warm water with or without bidet for 10 to 15 minutes:

• If necessary, antiseptics (gynecological betadine, liquid antiseptic soap, etc.) may be diluted in a bidet or bathtub.
• Spread the buttock slit open, clean the peri-anal folds. Be attentive to remove residual dirt in the folds and on hairs around the anus.
• Clean by hand, compresses, or with a damp cloth, without using a flannel.
• Dry gently with a cotton towel (dab) or with a hair dryer (blow-dryer) that is not too hot.

If necessary during the day and before sleeping, place a cotton cloth directly in the buttock crease or at the anus.

Shower immediately after exercise.

2. Clothing: 

• Cotton underwear, loose-fitting clothes to improve ventilation. Less sweat will also reduce moisture and irritation.
• Cut nails. If necessary, wear gloves at night to prevent scratching.

3. Diet and other rules: 

• Regulate intestinal transit (high-fibre diet if necessary).
• If necessary, take imodium® to reduce bowel movements in case of incontinence or loose stools.
• Stop or reduce consumption of alcohol, beer, chocolate, spices, tea, dairy products, coffee, tomatoes or other irritants (milk products in case of lactose intolerance).

4. Discontinue medications that stimulate itching (pruritus):

• Colchicine (gout), quinidine (antiarrhythmic), telaprevir (Hep C), neomycin (antibiotic).
• Gemcitabine (antibiotic)
• Ergotamine suppository (migraine), non-steroidal anti-inflammatory suppository.

5. Cream/ointment  

Barrier ointment

These ointments protect the skin and allow it to heal while reducing pain and irritation.

• Examples: Tena Proskin®,  A-Derma Dermalibour+ ®, Uriage Bariéderm®, Ducray Dexyane®, Cicalfate+®, Dermocrem®

Ointment based on corticosteroids

Ointment based on hydrocortisone 1% reduces local inflammation and thus pain and irritation.

Apply ointment, for 5 days to up to 3 weeks, twice daily

• Examples: Cremicort 1%®, Hydrocortisone cream 1%®, Conforma hydrocortisone 1%®, Pannocort cream 1%®

Capsaicin ointment

Capsaicin ointment reduces the transmission of pain at the level of pain receptors.

Application of the ointment produces (gives rise to )a burning sensation that diminishes over time, before having an effect on itching.

Application 3x/day for 4 weeks.

• Zacin Capsaïcine cream®   

6. Anti-histamine

In cases of severe itching, an antihistamine may be prescribed. Some antihistamines have a calming effect and may also help if the itching is accompanied by insomnia.

• Nustasium® 50mg (effet sédatif)
• Xyzal® 5 mg  

If anal pruritus resists all conservative treatments, temporary tattooing with methylene blue under general anesthesia in the day hospital may be considered.

The procedure involves injecting methylene blue into the dermis of the anal margin. The injection of methylene blue destroys the nerve endings in the skin that cause the itching.

Eusebio EB et al (1990) Treatment of intractable  pruritus ani. Dis Colon Rectum33:770-772
Farouk R et al (1997)  Intradermal methylene bleu injection  for the treatment of intractable idiopathic pruritus ani Br J Surg 84:670
Mentes BB et al (2004) Intradermal methylene blue injection for the treatment of intractable idiopathic pruritus ani: results of 30 cases. Tech Coloproctol !:11 -14

See surgical procedure: Anal margin temporal tattooing with methylene blue for anal itching