Pruritus Ani

Pruritus Ani means a chronic (persistent) itchy feeling around the anus. The main symptom is an urge to scratch your anus which is difficult to resist. The urge to scratch may occur at any time. However, it tends to be more common after you have been to the toilet to pass faeces, and at night (particularly just before falling asleep). The itch may be made worse by heat, wool, moisture, leaking, soiling, stress, and anxiety.

About 1 in 20 people develop pruritus ani at some stage. It is common in both adults and children.

What causes pruritus ani?

Pruritus ani is a symptom, not a final diagnosis. Various conditions may cause pruritus ani. However, in many cases the cause is not clear. This is called ‘idiopathic pruritus ani’ which means ‘itchy anus of unknown cause’.

Known causes of pruritus ani

There are various causes which include the following.

  • Inflamed anal skin is a common cause (a localised dermatitis). The inflammation is usually due to the skin ‘reacting’ to small amounts of faeces (sometimes called stools or motions) left on the skin, and/or to sweat and moisture around the anus. Young children who may not wipe themselves properly, adults with sweaty jobs, and adults with a lot of hair round their anus may be especially prone to this.
  • Thrush and fungal infections. These germs like it best in moist, warm, airless areas, such as around the anus. Thrush is more common in people with diabetes.
  • Other infections such as scabies, herpes, anal warts and some other sexually transmitted diseases can cause itch around the anus. You are likely to have other symptoms too such as a rash, lump or discharge.
  • Some diseases can cause generalised itch, which may seem more intense around the anus at times. For example, lymphoma, renal failure, iron deficiency anaemia, hyperthyroidism. With these conditions you are likely to be unwell with other symptoms too.
  • Skin conditions may also affect the skin around the anus to cause itch. For example, eczema, psoriasis, lichen sclerosus and seborrhoeic dermatitis.
  • Anal fissure. This is a small crack in the anal skin. It is usually painful as well as itchy.
  • Haemorrhoids (piles).
  • Threadworms are a common cause. Up to 4 in 10 children in the UK have threadworms at some stage. Threadworms live in the gut and lay eggs around the anus which cause itch. Children may pass them on to adults in the same home. Consider this cause particularly if there is more than one person in the home with an itchy bottom. (A separate leaflet discusses threadworms in more detail.)
  • Irritants. Some soaps, perfumes, creams, ointments, or the dye in some toilet tissue may sensitise (irritate) the skin around the anus in some people. You may be ‘allergic’ to one or more of the ingredients in these products.
  • Some foods are not fully digested and may sensitise the skin around the anus after going to the toilet to pass faeces. These include: citrus fruits, grapes, tomatoes, spices, and drinking large amounts of beer, milk, tea, or coffee.
  • Some medicines may pass through the gut and leak onto the anal skin and cause itch as a side-effect. For example, laxatives, colpermin, and some antibiotics.
  • A tumour of the anus or rectum is a rare cause of itch around the anus.

Idiopathic pruritus ani (of unknown cause)
In many cases, the cause is not clear. In some cases, it may be that something is ‘sensitising’ your skin (such as an ointment that you are using, or your sweat, or the toilet tissue that you use) but you cannot pinpoint the cause exactly. In some cases, the cause remains a complete mystery.

Pruritus ani and vicious cycles

A ‘vicious cycle’ sometimes develops. For example, you may have a mild anal itch. You may then clean your anus with a scented soap. This may contain an ingredient which sensitises your skin. You then get a worse itch. You may think the itch means the anus needs more cleaning, and so you clean it even more with the scented soap – which makes things worse, and so on.

Another example of a ‘vicious circle’ is: you may buy an ointment for ‘anal conditions’ if you have a small haemorrhoid (pile). This may contain an ingredient that your skin is sensitive to, particularly if your skin is already a little inflamed. It may sensitise the skin even more, and the itch becomes worse. You may think that the haemorrhoid has become worse, so you put on more ointment. But, in fact it is the ointment itself making the itch worse, and so on.

Most creams and ointments do not sensitise the skin in most people. However, be aware that there are many preparations with various ingredients, and you may become sensitive to one of them.

What should I do if I have pruritus ani?

If the itch is persistent and you are not sure of the cause, it is best to see a doctor. As there are a number of causes (listed above), it is best to be examined and checked out by a doctor to diagnose or rule out known causes. Treatment depends on the cause.

What is the treatments for pruritus ani?

If a cause is found

A particular treatment may be advised by a doctor or pharmacist. For example:

  • You may be advised to use a steroid cream for a short while if there is eczema (dermatitis) around the anus.
  • An antifungal cream will clear thrush.
  • Antibiotics may help with certain other types of infection.
  • Anal conditions such as haemorrhoids or anal fissure may need treatment.
  • A medicine can clear threadworms if they are the cause.

If there is no obvious cause (‘idiopathic pruritus ani’)
This is a common situation. The following tips often help to stop the itch.

  • Avoid any potential irritants
    • Stop using scented soaps, bubble bath, perfume, etc, near the anus.
    • Use plain, non-coloured toilet tissue. Wipe your anus gently after passing faeces.
    • Could any foods or medicines be causing the itch? Try avoiding for a while the foods and drinks listed above (such as fruits and tomatoes). Do you take laxatives regularly? Some may be leaking onto the anal skin.
  • Pay special attention to hygiene around the anus
    • Wash the anus after going to the toilet to pass faeces. The aim is to clear any remnant of faeces which may irritate the skin.
    • When washing around the anus it is best to use water only. If you use soap, use bland non-scented soap.
    • When you are not at home, use a moistened cloth or a special moistened tissue to clean the anus. You can buy moistened tissues from pharmacies.
    • Bath or shower daily. If possible, wash the anus with water only. If you use soap around the anus, rinse well.
    • Change your underwear daily.
  • Avoid excessive moisture around the anus
    • After washing, dry around the anus properly by patting gently (rather than rubbing) with a soft towel. Even better, use a hair dryer, especially if your anal skin is hairy.
    • Do not put on underwear until the anus is fully dry.
    • Wear loose cotton underwear (not nylon). Avoid wearing tight fitting trousers. If possible, do not sit for long periods, and try not to get too hot. The aim is to allow air to get to the anus as much as possible, and for it not to get too sweaty.
    • If you sweat and moisture gathers around your anus, put a tissue in your underwear to absorb the moisture.
  • Consider the ‘itch-scratch cycle’
    • Scratching can make the itch worse – which makes you want to scratch more, etc.
    • As much as possible, try not to scratch. This is especially difficult at night when the itch tends to be worse when you are trying to get to sleep.
    • You may also scratch in your sleep without realising. To help this:
      • Keep your fingernails short to limit any damage done to the skin by scratching.
      • Consider wearing cotton gloves at night to prevent sharp scratching with fingernails.
      • An antihistamine medicine that makes you drowsy may be worth a try at bedtime. Your doctor will advise.
  • Your doctor may advise a short course of a cream or ointment
    • A bland soothing ointment may be recommended to use after going to the toilet and at bedtime. There are many to choose from. (However, remember an ingredient of an ointment may sometimes cause sensitivity and itch around the anus.)
    • A short course (5-7 days) of a mild steroid cream may ease symptoms if there is inflammation of the anal skin. Steroids reduce inflammation (but should not normally be used on infected skin).

Other possible treatments

The above measures will usually stop the itch. If symptoms persist for 3 or 4 weeks after doing the above, then your doctor may refer you to a skin specialist. Tests may be needed to make sure a known cause has not been missed.

Other treatments are being researched. For example, a treatment that shows promise for severe pruritus ani not helped by other treatments is injections of methylene blue into the itchy skin. Further research is needed to clarify the place of this new treatment.

A final note

Pain or other symptoms such as bleeding from the bowel, mucus discharge, or lumps around the anus are not symptoms of straightforward pruritus ani. See a doctor if these or other symptoms develop in addition to itch.