AREAS OF EXPERTISE

What is Pruritus Ani?

Pruritus Ani is the medical term for intense itching around the anus that leads to the strong urge to scratch the bottom. Up to 5% of the population is estimated to be affected and the condition is more common in men than in women.

What causes Pruritus Ani?

There are many possible causes of Pruritus Ani.

One cause is incontinence of stool. This can be due to loose stools and diarrhoea or amounts of stool so small that they are undetectable. Itching is also commonly associated with other conditions such as haemorrhoids, anal fissures and anal fistulas. Bacterial and fungal infections are responsible for some cases of pruritus ani. Some of these infections can be transmitted sexually. Some medications such as steroid creams, antibiotics and some haemorrhoid treatments can cause or worsen symptoms.

Pruritus ani may be associated with skin conditions such as psoriasis and contact dermatitis. Contact dermatitis is skin that is very sensitive to chemicals found in cleansing products such as soap. Common conditions such as diabetes, anaemia, kidney and thyroid disorders can also cause itching. Very rarely and itchy bottom can be caused by a cancer of the skin around the anus.

Some foods and drinks such as tomatoes, chocolate, citrus fruits, spices, coffee, tea, alcohol and milk are known to cause itching in some people. In others, itching can be precipitated by stress, anxiety and depression.

In some cases no cause can be identified. This is called idiopathic pruritus ani.

Do I need to see a Doctor?

If you are experiencing itching around the anus, it is recommended that you see your GP to find out the underlying cause and to exclude any other conditions.

Your GP will ask you several questions to find out more about your symptoms. This is likely to include questions about your diet, bowel habit, personal hygiene, sexual history and other genital symptoms that will help your doctor reach a diagnosis.

Will I need to be examined?

The GP is likely to want to examine your bottom. As well as inspecting the skin around the anus, an examination of the genitals is useful to identify anything that you have not yet noticed. The   doctor may perform a digital rectal examination which involves placing a gloved and lubricated finger inside the rectum to look for things that may be causing the itching. This should not be painful but may feel uncomfortable. At this point swabs may be taken to check for infection.

How is Pruritus Ani treated?

For those cases of Pruritus Ani with an underlying cause, the goal is to find this cause and treat it. This may require referral to a specialist dermatologist for those with suspected skin conditions or a colorectal surgeon for those with suspected ano-rectal disease.

For some people in whom a cause is not identified. Lifestyle changes are recommended to stop or improve symptoms. These include:

Keeping the area clean and dry. Have a bath or shower daily. After passing stools, clean the area with lukewarm water using a wet cloth, shower or bidet. Do not use soap antiseptics or scented products on your bottom. Dry by gently patting a soft cloth, unbleached toilet paper or by using a hairdryer on a low setting. Wearing loose cotton underwear is recommended.

Dietary changes are often necessary for treatment.  There are several common foods which may be related to pruritus ani.  These foods and beverages include coffee, colas, tea, chocolate, tomatoes and beer.  These items may possibly decrease your sphincter tone which can cause some seepage or leakage.

It may be helpful to remove one item at a time from your diet for several weeks.  If your symptoms improve, you could try reintroduction of the item in smaller volume and see if there is a limit to which you may have that item without producing symptoms.

Improving the consistency of stools by altering fibre and fluid intake.

Avoid scratching although this may be very difficult. Prevent inadvertent night time scratching by keeping fingernails short or wearing gloves to bed.

A skin barrier cream such as zinc oxide may also be helpful in protecting the skin around the anus from irritants. Additional topical agents such as numbing medications, menthol, phenol, camphor, or a combination of them may be helpful.

Your doctor may prescribe creams or ointments containing steroids or other substances. This will improve symptoms for most people. If this is not the case, make sure you inform your doctor.