Pruritus Ani

Pruritus Ani


What are the aims of this leaflet?

This leaflet has been written to help you understand more about pruritus ani. It will tell you what it is, what causes it, what can be done about it, and where you can find out more about it.

What is pruritus ani?

‘Pruritus’ means itching. Pruritus ani is itching around the opening of the back passage (the anus). It is a symptom with many causes, but sometimes no obvious cause can be found. Pruritus ani is common and occurs more often in men than women. It is seldom due to an underlying serious condition and those who have pruritus ani are usually otherwise well.

What causes pruritus ani?

Pruritus ani has many possible causes, so it is sensible to seek the advice of your doctor about your own itching.
Some of the more common causes are:

  • Anal disease. The contents of the bowel contain digestive enzymes that can irritate the skin and cause itching. Minor leakages of bowel motions, and a failure to remove them completely from the skin around the anus, can lead to pruritus ani. One contributory factor may be the presence of piles (haemorrhoids), which are the result of back pressure on the blood vessels of the anal area. Constipation (not opening the bowels regularly) can make the piles and pruritus ani worse. Skin tags in the anal area can also contribute to itching.
  • Skin disease around the back passage. Examples of this include psoriasis, eczema, thrush (a Candidal yeast infection), and fungal infections.
  • Threadworms. In children, itching around the back passage is often due to threadworms, which can cause pruritus ani in adults too. The itching is usually worse at night.
  • Allergy. Pruritus ani may be due to an allergy to something in contact with the skin, for instance to scent in toilet paper, or to local anaesthetics or preservatives in creams used for piles.
  • Skin irritation. The skin of the bottom is sensitive and can easily be irritated by moist wipes, soaps, perfumes, antiseptics (for example, Dettol). These make the skin sore and itchy and contribute to pruritus ani.
  • Sweating. The skin around the back passage is often moist with sweat. If long periods pass without ventilation to the area, for instance if you sit down for a long time, the skin can be irritated further and become itchy.

Is pruritus ani hereditary?


What are the symptoms of pruritus ani?

Itching is the main symptom, often occurring after the bowels have opened. It may be bad enough to interfere with sleep. Sometimes the skin becomes sore after scratching, making it uncomfortable to open your bowels.

What does pruritus ani look like?

The skin around the anus may look inflamed and thickened, and show scratch marks. Small cracks may occur and these may feel painful and sensitive, and bleed.

How is pruritus ani diagnosed?

It is usually possible to make a diagnosis of pruritus ani by hearing the story and examining the affected skin. Your doctor will want to find out why you have pruritus ani, and may need to check you for threadworms, allergies etc. The tests selected will depend on the clues offered by your story and the examination of the skin in the area.

Can pruritus ani be cured?

There is no one simple treatment that will cure everyone who has pruritus ani as it can have so many different causes. It is important to diagnose these correctly and then the right treatment can be implemented.

How can pruritus ani be treated?

  1. The first step will be to find out if any of the causes listed above are playing a part in causing your pruritus ani. If they are, then your doctor will treat them appropriately.
  2. If no obvious cause can be found, your doctor may suggest a variety of ways of helping your pruritus ani:
  • A steroid ointment or cream applied every day to the area for a short course may reduce the itching. It can be used intermittently as and when needed.
  • An antihistamine may be prescribed by your doctor as a course to relieve itching.
  • It is important to remove all irritants such as bowel motions or soap from the skin creases. A cream, such as aqueous cream, should be used instead of soap for washing the area. This avoids the irritating effect of soap and detergents. Cotton wool balls with warm water are gentler than toilet paper and more effective in cleaning fissures and creases. The area also should be rinsed thoroughly after you have opened your bowels.
  • If you have troublesome constipation, you should see your family doctor for advice.

What can I do?

  • You should avoid any of the things listed above that might be contributing to your pruritus ani. If you notice that a particular food makes the itching worse, avoid it.
  • Scratch as little as possible, as scratching keeps the itch going.
  • Open your bowels regularly. Try not to delay going to the toilet when you have the urge to do so.
  • Keep your stools soft so you do not have to strain to open your bowels. Eat plenty of fruit, vegetables and other roughage, and drink plenty of water.
  • The use of a bidet or a shower jet helps to remove particles of bowel motion that have become trapped near the anus. Always dry the skin gently, without rubbing it.
  • Keep the area as well ventilated as possible. Clothing should be loose and not made of synthetic materials. Avoid prolonged sitting.

Where can I get more information?
Web links to detailed leaflets: