Pruritus ani
What is pruritus ani?
The term “pruritus ani” refers to an ‘itchy bottom’.
This is a common and distressing problem for many people. It occurs most commonly in middle-aged white men. There are many simple things that can be done to help ease the symptoms. However, treatment may not completely cure the problem.
What causes pruritus ani?
Pruritus ani can be caused by skin conditions such as eczema, psoriasis, lichen planus, lichen sclerosus or by other factors such as haemorrhoids or bowel problems such as “anal fissure”. In young children or parents of young children, pinworm infection is a common cause. Other infections such as herpes or candida can also be responsible. Some health problems such as diabetes or underactive thyroid may also cause itching.
What does pruritus ani look like?
The skin is often non-specific in appearance. In acute cases the skin can be red, scratched and even have fissures, which can be painful. In chronic cases, the skin can become thickened through rubbing and scratching.
What other problems can occur with pruritus ani?
Repeated itching and scratching can cause an ongoing itch-scratch-itch cycle.
How is pruritus ani diagnosed?
The diagnosis is usually made by observation and history taking by your GP. Infection can be excluded by taking a swab of the affected area. If there is a rash visible, a dermatologist may be helpful in diagnosing the condition. A colorectal surgeon may need to be seen for a telescope test known as a “proctoscopy”.
How is pruritus ani treated?
- Stop using all over-the-counter preparations
Products such as Anusol®, Rectinol® etc contain anaesthetics and preservatives that can actually make the condition worse. Some medications prescribed by your doctor can also cause an allergic reaction.
- Stop scratching
This is easier said than done. Repeated scratching and rubbing will lead to thickening of the skin (lichen simplex chronicus) and ongoing itch. It is important to break the itch-scratch-itch cycle.
- Stop using soap
Soap, shampoo, bubble baths etc remove all natural oils from the skin making it dry and itchy. In the shower or bath use a soap-free wash and use low soap shampoo such as Dermaveen®, Aveeno®, and QV® etc. Avoid over washing the area. Avoid long hot baths or showers. Hot spas and swimming in chlorinated pools can also irritate the skin.
- Toilet paper tips
Soft, non-perfumed toilet paper should be used. Avoid harsh wiping, as this will damage the skin. Some people find that wiping with cotton wool balls dipped in water is better than using toilet paper.. Others find that a quick, cool shower after going to the toilet can help. If sweating makes the itching worse, folding a tissue into a small square and placing this on the area to absorb excess moisture during the day may be helpful.
- Clothing
Avoid nylon underwear. Men should wear 100% cotton boxer shorts only.
- Diet
Some people find that hot or spicy food containing chilli exacerbates the itch. A high fibre diet may also be useful if loose bowel actions are a contributing factor.
- Work
Avoid vinyl or leather chairs if your occupation involves lots of sitting. The best type of chair is one with an open weave such as a woven rattan. Alternatively, placing a folded cotton towel on the seat can help.
- Colorectal surgeon
Although it is unlikely that surgery will be needed, a colorectal surgeon is the best person to perform a “proctoscopy”. A short telescope is inserted into the anus to look for simple things that can cause itching such as a small tear (anal fissure), skin tags, haemorrhoids, warts, anal sphincter problems etc.
- Dermatologist
A dermatologist will examine the area as well as other parts of the body to determine if the itch is being caused by a skin condition such as eczema or psoriasis. These common skin conditions cause pruritus ani. However, there are many other causes.
Occasionally a skin biopsy needs to be taken to rule out these other causes. Allergy testing (patch testing) may be required. Blood tests can occasionally be helpful (eg to check for diabetes). Low strength steroid ointments are often required. Strong steroid ointments should be avoided in this area as they can cause skin thinning after long-term use.