An itchy bottom may be just an annoyance, or may be so bothersome that it dominates your life. It is usually made worse by warmth, and is often most troublesome in bed. The skin around the anus easily becomes irritated and inflamed. This is because it is difficult to keep the area around the anus clean and dry; the skin is crinkly and traps tiny particles of poo. It is also sweaty and relatively airless, and it may become moist from an anal or vaginal discharge. When it becomes irritated, scratching is a natural reaction, but this damages the skin further – the itch/scratch cycle. Ointments and creams can sometimes cause further problems by keeping the area damp.
Although it is very unpleasant, anal itching seldom means anything serious. If you have pain as well as itching, look at the section on anal pain.
Anal itching can occur at any time of life, but seems to be most common between 30 and 50 years of age. It is four times more common in men than in women.
Causes of Anal Itching
Washing too much or not enough. Poor hygiene can be responsible for anal itching, but so can excessive cleaning, especially if you use harsh soaps or rough toilet paper or towels.
Leakage of poo can lead to itching around the anus because prolonged contact with mucus in the poo causes irritation of the skin (Annals of the Royal College of Surgeons of England 2008;90:457–463). About half of all people with anal itching tend to have loose faeces. Look at the section on faecal incontinence for more information.
Anal conditions (particularly piles) can have itching as one of their symptoms, partly because of the slimy discharge they produce. Look at our section on piles (haemorrhoids) for more information.
Pre-moistened toilet tissues (wet-wipes), bought from chemists and supermarkets, can sometimes cause anal itching. The reason is probably the perfume, alcohol or preservative in the wipes.
Sensitivities and allergies to other chemicals, such as bubble baths and perfumed soaps, may be responsible.
Ointments and creams are notorious causes of anal itching. If you have itching, it is a natural reaction to buy an anaesthetic gel for the anal area. Most of these are labelled ‘for haemorrhoids’ and contain lignocaine, tetracaine, cinchocaine, pramocaine or benzocaine with other ingredients. At first they help, but then the itching may return because you have become sensitive to one of the ingredients in the cream or ointment and they are keeping the area moist. Do not use them for more than 1 week without seeking medical advice.
Skin conditions, such as psoriasis or eczema, or a condition called lichen sclerosis, can affect the skin around the anus and cause itching. Lichen sclerosis is a condition that can progress, therefore it is important to seek medical advice for a persistently itchy bottom.
Fungal infections, similar to thrush or athlete’s foot, are another common cause. Fungi love warm, damp and damaged skin, so if you have an itchy anus and damage the skin by scratching, fungi can take hold and make it worse.
Sexually transmitted and other infections
- Genital warts (on the vulva or penis), caused by papillomavirus, thrive in warm, moist conditions such as the skin near the anus, and can be very itchy.
- Genital herpes (caused by herpes virus) can also infect the anus, and causes itching just before the sores appear and also during the healing stage.
Both these viruses are easily transferred to the anal skin on the fingers, and can therefore occur around the anus in anyone. The anus may be the only site of infection; the fact that you do not have genital warts or herpes elsewhere does not rule them out. Various bacteria (such as some staphylococci or streptococci) can cause anal itching; the skin will be red and inflamed, and usually needs antibiotic treatment.
Threadworms (pinworms) are tiny worms, 2–13 mm long, which live in the lower part of the bowel. They are very common – up to 40% of children in the UK have a threadworm infection at some point in their lives. The female worms creep out of the anus at night – how they know it is night, and why they come out only at night, is a mystery. They lay thousands of eggs on the skin of the anus, causing intense itching at night. When you scratch, the eggs lodge under your fingernails, and it is easy to transfer them to your mouth and reinfect your gut by swallowing the eggs. If several people in the family have anal itching, threadworms might be the cause.
Certain foods can irritate the anus during defecation. Beer and chili peppers are obvious examples. Some people find that milk, citrus fruits, grapes, tomatoes, coffee or tea can cause problems.
Tight trousers or underwear, especially synthetic and elasticated fabrics, retain heat and sweat, which worsens itching.
Anxiety tends to make the brain hyper-alert to body feelings that we may otherwise be able to ignore. If you are going through an anxious period, a symptom such as itching can become magnified.
How You Can Help Yourself
- Wash the anal area after you have had your bowels open, using just water or an unperfumed soap. Some doctors recommend using a bland emollient such as aqueous cream (available from pharmacies) as a cleanser. Apply the cream, massage it gently over the area and then rinse off. If you are somewhere where you cannot wash, clean the area with wet tissues (but not with pre-moistened wipes containing perfume, alcohol or other irritants). If you use shower gel or soap to wash your body, make sure you rinse it off very thoroughly so that none remains between the buttocks.
- Dab gently with a soft towel to dry – do not rub. If drying is difficult, use a hairdryer on a cool setting.
- Do not put any disinfectant on the skin or in the bath water – this can irritate the skin. Do not use bubble bath – the perfume can irritate. Instead, put a handful of kitchen salt in your bath.
- Wear loose cotton underwear. Avoid tights and elastic ‘shapewear’ underwear, because they can encourage sweating and moistness in the anal area. Avoid anything that keeps the buttocks close together.
- Try not to scratch. If you scratch, you damage the skin more and then you itch more. People often scratch at night and do not realize they are doing so. If you think you might be scratching at night, talk to your doctor about taking an antihistamine, keep your fingernails short, wear cotton gloves at night for a while and ask your doctor to check for threadworms.
- Do not use any greasy creams (such as Vaseline) on the area. Greasy creams keep the skin soggy and make the problem worse. Zinc oxide cream (from pharmacies) can be soothing if the skin has been damaged by scratching.
- Be very cautious about anaesthetic creams or ointments. Sometimes they can help by relieving the itch/scratch cycle, but use them only for a short period (about a week).
- Similarly, be very cautious about steroid creams. In the UK, it is possible to buy weak steroid cream (containing hydrocortisone 1% or less) from pharmacies. In the short-term, the steroid reduces inflammation and therefore relieves itching but, in the long-term, it can make the skin thinner and worsen the problem. Resist the temptation to keep on using a steroid cream. Use it for just 1 week, then throw the tube away.
- Feel around the anus for lumps. This may not be easy, because the skin around the anus is normally puckered. A lump might be a wart, a pile or a skin tag, or very occasionally it can be the sign of anal cancer.
- Avoid foods that cause excessive flatulence (wind).
How Your Doctor Can Help
If you are anxious about being examined by your doctor, look at the section on seeing your doctor about an anal problem. Your doctor can check to see whether you have any conditions such as piles (haemorrhoids), fissure, warts, psoriasis, eczema, fungal infections or other conditions that need treatment.
- If you scratch at night, an antihistamine taken before you go to bed can help. Antihistamines relieve itching and some also tend to make you drowsy.
- Discuss with your doctor whether you might have threadworms (pinworms). They look like small threads of slow-moving white cotton. These can be eliminated with mebendazole. The treatment may need to be repeated after 14 days because the eggs can persist for this length of time in the environment (NHS MeReC Bulletin 2008;18:11–13; NICE British National Formulary (BNF)). The other members of your household will also need to be treated. You should also wash your hands and scrub your nails before eating and after each visit to the lavatory, and wash the anal area in the morning to get rid of any eggs deposited during the night.
- An ointment containing a chemical found in chili peppers (capsaicin) may be an effective treatment for very troublesome anal itching (International Journal of Dermatology 2010;49:858–865), but the researchers used a special very dilute ointment (0.006%) that is not generally available (Annals of the Royal College of Surgeons of England 2008;90:454–463).
- If nothing helps, your doctor might consider referring you to a specialist for injection of a chemical called methylene blue into the anal area. So far, research has involved only a small number of patients, but the itching improved in most patients and disappeared completely in half (Colorectal Disease 2009;11:282–287). More research is awaited to find out how long the relief will last.
First published on: embarrassingproblems.com
Reviewed and edited by: Dr Kevin Barrett
Last updated: October 2020