Itchy anus

Introduction

Itching of the skin about the anus is a common complaint. When no underlying skin condition is found, the term 'pruritus ani' may be used.

Anal itching is usually an isolated skin complaint in otherwise healthy persons, but in some, it is part of a disorder involving other areas of the skin, especially the vulva in women and children.

What causes an itchy anus?

Common conditions affecting the anus and contributing to itch include:

• Dermatitis, including irritant contact dermatitis and allergic contact dermatitis
• Psoriasis
• Seborrhoeic dermatitis and other causes of intertrigo
• Lichen sclerosus
• Bacterial infection including streptococci (streptococcal dermatitis) or Corynebacteria minutissimum (erythrasma)
• Yeast infection especially Candida albicans
• Pinworms
• Excessive perianal hair growth
• A deeply set, funnel-shaped anus.

The anal skin is exposed to irritating digestive products which may result in a rash (irritant dermatitis). The rash is made worse by:

• Frequent stools (diarrhoea)
• Straining at stool (constipation)
• Scratching
• Vigorous use of toilet tissue
• Wet pads used to cleanse the anus
• Pads or panty liners
• Scrubbing with soap and water
• Acidic or spicy foods
• Potential or confirmed allergens (eg, methylisothiazolinone or another preservative in cleansing pads, fragrance in toilet tissue).

What is the treatment of an itchy anus?

Specific treatment may be prescribed for infection, infestation with pinworms, or certain skin conditions. General measures are described below.

• Irritation of the anal skin needs to be reduced. It is impossible to eliminate it altogether because the stool continues to be in contact with the inflamed skin.
• Cleanse carefully, thoroughly and gently after bowel movements. If there is faecal leakage, cleanse again after an interval of half an hour.
• Wash the anus using an electronic bidet-toilet, standard bidet, shower or a bucket of lukewarm water. Moistened preservative-free dry wipes or soft toilet paper are next best. Use aqueous cream, mineral oil or another soap-free cleanser.
• Avoid soap and rough toilet paper.

• Apply medicated ointment as directed.
• Ask your doctor to explain your treatment. Various different soothing preparations are suitable, including mild topical steroids and zinc paste. Strong steroid creams should not be applied for more than a few days unless under strict medical supervision.
• Petroleum jelly or a baby nappy/diaper barrier cream can be applied frequently to soothe and to act as a barrier preparation and skin protectant, especially for faecal leakage or diarrhoea.
• Do not apply any other remedy, suppository, or medicine to your rash. They can cause allergic contact dermatitis.

• Avoid constipation.
• Eat plenty of high fibre foods (cereals, fruit and vegetables). Straining at stool causes cracks in the anus which are irritable and harbour bacteria.
• Avoid excessively loose or otherwise irritating motions.
• Don't over-indulge in spicy food, prunes, figs, orange juice, coffee or beer.
• Avoid scratching. Scratching and rubbing are common reasons for continuing pruritus ani.

Itching of the anus is frequently persistent and recurrent. The above advice should be followed indefinitely.