Pruritus ani means a chronic (persistent) itchy feeling around the anus. About 1 in 20 people develop pruritus ani at some stage. It is common in both adults and children.

What causes pruritus ani?

Various conditions may cause pruritus ani and include those listed below. However, in many cases no cause can be found.

Inflamed anal skin is the common cause (a localised dermatitis). The inflammation is usually due to the skin 'reacting' to small amounts of stool (sometimes called faeces 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 bugs like it best in moist, warm, airless areas, such as around the anus. Thrush is more common in people with diabetes.
Skin conditions may also affect the skin around the anus to cause itch. For example, eczema and psoriasis.
Anal fissure. This is a small crack in the skin of the anus. 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 can 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 a stool. 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. For example, laxatives and some antibiotics.
A tumour of the anus or rectum is a rare cause of itch around the anus.

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.

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 things worse.

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 are 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 mild steroid cream for a short while if there is inflammation (dermatitis) around the anus.
An antifungal cream will clear thrush.
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 then the following tips often help.

Stop using scented soaps, bubble bath, perfume, etc, near the anus.
Use plain, non-coloured toilet tissue, and bland non-scented soap.
Wash the anus after going to the toilet to pass a stool. When you are not not at home, use a moistened cloth or a special moistened tissue that you can buy from pharmacies.
Bath or shower daily. Rinse and dry around the anus properly. Do not put on underwear until fully dry. If your anal skin is hairy, a hair dryer may be useful to dry it after washing.
Are any foods or medicines causing the itch? Try avoiding fruits and tomatoes for a while. Do you take laxatives regularly? Some may be leaking onto the anal skin.
Use a bland soothing ointment after going to the toilet and at bedtime. There are many to choose from. A pharmacist will advise. However, remember an ingredient of an ointment may sometimes cause sensitivity and itch around the anus.
Wear loose cotton underwear, and 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, and not to get too sweaty.
Change your underwear daily. If necessary, put a tissue in your underwear to absorb moisture.

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.

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

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