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Pruritus Ani


Anal irritation is a very common condition in men and women. The medical term for this condition is “pruritis ani”.

SYMPTOMS

The main symptom is an intense urge to scratch your anus, which may be difficult to resist. It often is worse at night. Scratching increases itching, as small wounds that occur will trigger more itching on infection or healing.

WHAT CAUSES IT?

In some people, the irritation is a reflection of a more generalised skin condition such as eczema or psoriasis.

However in many cases itching and skin irritation are associated with problems of the anal canal like haemorrhoids, anal fissure, anal fistula or prolapse of the bowel lining. In these conditions small amounts of stool or mucus leak out of the anal canal and get onto the anal skin, causing soiling. The chemicals in the stool cause low-grade infection. The skin around the back passage is very delicate and sensitive. When bowel motions are frequent and loose the skin in the perianal area can become red, sore, itchy and prone to bleed.

There are several main causes of skin problems:

  • Excess moisture: due to excessive sweating, wet pads, urine and stool
  • Chemical irritation: by soaps, skin care products (especially those containing fragrances and alcohol), urine and digestive juices/acid in stool
  • Mechanical damage: from too much wiping and rubbing, especially with dry toilet paper and rough washcloths
  • Infection: by bacteria or fungi that take hold when the skin is damaged.
  • Threadworms: small, thread-like worms that cause intense itching around the anus, usually at night, sometimes seen in stool or on bedsheets. They are a common cause of itching in children, but do also infect adults.

WHAT TESTS DO I NEED?

Examination in clinic can be all that is needed to determine the cause. Sometimes we recommend a colonoscopyanorectal physiology & ultrasound studies or a proctogram to investigate possible underlying causes in your bowel or pelvic floor.

In a small number of cases, no cause is found. Than the condition is said to be ‘idiopathic’ or of unknown cause.

WHAT ARE THE TREATMENTS?

If there is evidence of haemorrhoids, fissure, fistula or prolapse then we will treat these problems accordingly.

Skin irritation caused by loose and/or frequent bowel motions can be treated by slowing and firming up your bowel motions (see Loperamide).

If there is an evident underlying skin problem, we may recommend referral to a dermatologist.

Threadworms are usually easily treated with an over-the-counter medicine, although young children and pregnant or breastfeeding women should seek advice from their GP. Re-infection can be prevented by following a hygiene routine. A good source of guidance can be found at: 
http://www.nhs.uk/Conditions/Threadworms/Pages/Introduction.aspx

WHAT CAN YOU DO TO HELP YOURSELF?

Pruritus ani can be difficult to treat, and it may take many months of gentle care to improve the symptoms. There are some things you can do to help. The two key principles of treating skin problems are gentle cleaning and preventing breaks in the skin or, if already damaged, helping the skin to heal.

Try to avoid scratching the area, however tempting this may be. Some people scratch themselves severely during the night when they are asleep. This leads to skin ‘excoriations’ or wounds. Sometimes wearing mittens or cotton gloves for a few nights allows the skin to heal and can break the vicious circle.

CLEANING THE SKIN

Although hygiene is important, many people with pruritis ani are overzealous with cleaning. It is essential that all washing and drying is done gently to avoid damage to the skin. Regular baths, bidet use or washing in the shower after each bowel motion will help. Generally twice a day and after each bowel motion or leakage should be sufficient. Skin should be thoroughly dried after washing.

Some useful tips:

  • Skin should be cleaned with plain warm water or products that are skin-neutral or ‘pH-balanced’. They should NOT contain soap, alcohol or fragrance. Use of soap removes the natural skin oils and increases the pH of the skin. This weakens the skin, increases the risk of skin breakdown and slows healing. Special skin care cleansers are available from your pharmacy or from medical supply companies.

  • Dry toilet paper and rough washcloths can easily damage the skin. Always pat dry, do not rub. Non-alcoholic baby wipes can be used to gently clean the perineal area, but some people are sensitive to excessive use of these products so use with caution. “Flushable’ toilet wipes from supermarkets should also be used with caution as many contain alcohol or fragrance.
  • Reduce sweating by wearing loose fitting clothes and pure cotton underwear rather than synthetics (polyester, lycra or nylon). Change your underwear frequently, at least daily. Wash your underwear in non-biological washing powder, and make sure that all trace of detergent is rinsed out. Ladies might want to wear stockings in preference to tights.
  • Certain foods may accentuate anal irritation, including tea, coffee, chocolate, hot and spicy foods, nuts, raw fruits and vegetables. Try to avoid these.
  • For people with incontinence, super-absorbent pads or underwear should keep leakage away from the skin. Frequent changing is necessary. It is best to avoid using women’s sanitary products because these are not designed to absorb faecal matter effectively.
  • Take care with drying – some patients dry too vigorously and cause damage to the skin. Many of our patients find that using a hairdryer is helpful if skin is very delicate.

SKIN CARE PRODUCTS

It may be helpful to apply products to your skin, but follow these guidelines: 

  • Avoid using creams or lotions unless prescribed or suggested by your doctor. These products are usually not necessary unless in cases of substantial incontinence with/without skin break down.
  • Moisturisers are best avoided. They replace oils in the skin but may contain ingredients such as glycerine, mineral oil or paraffin. Emollients such as lanolin are often added to soften dry skin and make it feel smooth. However lanolin can cause allergic reactions in some people.
  • Barrier creams and ointments form a protective coating on the skin. They can contain petrolatum, dimethicone or zinc oxide. Zinc oxide gives the best protection against faeces, but is difficult to remove. Sudocrem is a useful form of zinc oxide cream, often used for nappy rash in babies. It is available from supermarkets and pharmacies.
  • Do not use talcum powder because it can cake in skin folds and can cause skin damage.
  • Anti-fungal creams and hydrocortisone (steroid) ointments should not be used without careful assessment by your doctor.

WHAT IF ALL MY MEASURES ARE NOT HELPING?

If all causes have been excluded and/or treated, ‘idiopathic’ itching may benefit from the injection of a blue dye (methylene blue) into the anal skin. The dye is ‘neurotoxic’, which means that it numbs the nerve endings of the anal skin. The downside of this treatment is that the skin around the anus will appear blue for at least several months, possibly for years, and you can experience long-lasting numbness around the anus.


Please be advised that the information on this website is not a substitute for professional medical advice, diagnosis or treatment