Itchy bottom

Nobody talks about this, which is why people usually turn up at a consultation about six months in, having worked through half a dozen creams and washed three times a day — mostly making things worse. It can be sorted out far quicker than that: there are only a handful of causes, they are recognisable, and most of them are harmless. A few are not, and those are worth knowing by sight. What follows is plain and to the point: why it happens, what genuinely helps, what only drags it out, and when the answer is not another ointment but an examination.

Why this particular spot itches

The skin around the anus is thin, folded, almost always warm and damp, and in constant contact with bowel contents. Even the smallest traces of stool left in the folds irritate it, because the enzymes in stool are harsh on skin. Add sweat, tight underwear, synthetic fabrics and hours of sitting, and you have an environment where irritation starts easily and settles slowly.

Then the loop starts that turns the itch chronic. You scratch — usually asleep, without knowing it — the skin is damaged, its barrier weakens, and the itch intensifies. Scratch marks weep, bacteria or fungus move in, the skin thickens and now itches on its own account, regardless of how the whole thing began. So there are almost always two jobs: the original cause, and the loop.

Stool deserves a separate mention. Loose motions, frequent trips to the toilet, mucus leaking, marks on the underwear, slight loss of control over wind or stool — these are the strongest irritants this skin ever meets. If any of that is happening, the itch is almost certainly a consequence, and the bowel is what needs attention, not the skin.

The washing that makes it worse

The commonest cause of a long-running itch here is over-washing, and people generally do the exact opposite of what is needed. The reasoning is understandable: it itches, so it must be dirty, so wash more and harder. In fact soap strips the greasy film that protects the skin, hot water finishes the job, and brisk towelling takes off the surface layer. The skin is left defenceless and itches more — so the washing gets more thorough still.

Wet wipes work the same way. They contain fragrances and preservatives that cause contact dermatitis in their own right, and rubbing a wipe over already irritated skin does more harm than the trace of stool it was meant to remove. Here wipes are not the fix but the cause: people who switched to them in the name of cleanliness often started itching from exactly that point.

The third source is the anti-itch products themselves: ointments and suppositories with local anaesthetics (in the ingredients list they usually end in "-caine"), haemorrhoid creams, antiseptics, spirit-based lotions, essential oils, powders and scented toilet paper. All of them can produce allergic contact dermatitis, and the pattern is deceptive: relief at first, then a week or two later the itch comes back harder, and the person concludes they are not applying enough and applies more. The same goes for steroid creams: a short course on a doctor's advice is reasonable, but months of use thin the skin and keep the itch going by themselves.

Hence the first move with any persistent itch: for one week take everything away — wipes, soap, ointments, powders, scented paper — and keep nothing but warm water and patting dry with a soft towel.

Threadworms and why the whole household is treated

In a child who scratches at night, threadworms are the first thing to think of. They are white worms a few millimetres long, like short pieces of cotton thread. The female comes out at night and lays eggs in the skin folds around the anus, which is where the classic night-time itch comes from, the one that has the child restless and sleeping badly. Sometimes the worms are visible in the stool, or on the skin if you look an hour or two after the child falls asleep.

Passing them on could hardly be easier: the child scratches, eggs collect under the fingernails, then travel to hands, toys, bedding, door handles and crockery, and into the next mouth. That is why threadworms are almost never confined to one person.

Everyone in the household is treated on the same day, whether or not they have symptoms. Treating them together is the whole point: treat the child alone and the symptom-free relatives will hand the worms straight back within a week. A doctor prescribes the medicine or a pharmacist advises on it; children under two, pregnant women and women who are breastfeeding need advice from a doctor of their own. The dose is usually repeated after two weeks, to catch anything that hatched after the first one.

Tablets alone are not enough. On the same day and for the fortnight after: keep nails cut short, wash hands after the toilet and before meals, put the child in close-fitting pants at night so they cannot scratch in their sleep, wash the area and change their underwear each morning, launder bedding and pyjamas without shaking them out (the eggs scatter around the room), and wipe surfaces and toys with a damp cloth often. If the itch is still there a month later, it is either reinfection or a different cause — which calls for an examination, not a third course of tablets.

Piles, fissures and what goes on inside

The second large group of causes sits not on the skin but inside the anus itself.

• Piles. They make it impossible to wipe clean and they produce mucus, and internal piles that come outside keep the skin permanently damp. The clue is bright red blood on the paper or on the surface of the stool, and a feeling of not having finished.
• Anal fissure. Sharp, cutting pain during a bowel movement and for a long while afterwards; the itch arrives later, as the fissure starts to heal. Nearly always tied to hard stools and straining.
• Skin tags, the painless folds left behind by piles or a fissure: harmless in themselves, but moisture and traces of stool collect between them.
• Fistula and abscess: continuous discharge of pus or blood-stained fluid and, with an abscess, mounting pain, swelling and fever as well.
• Leakage of stool and prolapse of the lining. Even a trickle the person is unaware of keeps the skin wet round the clock.

What they all have in common is that a cream on the skin settles nothing, because the source of the wetness is inside. You need an examination and work on the cause, stool included: soft, formed motions passed without straining will on their own heal both a fissure and piles.

When the cause is a skin disease

Skin around the anus gets the same diseases as skin anywhere else; it just looks different, because in a damp fold there are no dry scales and everything simply looks red and sodden.

• Eczema, usually in someone who has it elsewhere as well: inside the elbows, behind the knees, on the hands.
• Flexural psoriasis. Unlike psoriasis on the elbows, the patches here are smooth, deep red, sharply outlined and not scaly. The clue is generally on the elbows, knees, scalp and nails.
• Fungal infection: a red patch with a raised edge spreading into the groin and thighs. Commoner with diabetes, with excess weight, and after a course of antibiotics.
• Lichen sclerosus and lichen planus. The skin looks pale, thinned and shiny, and splits easily. This is not "just irritation": these changes need medical follow-up, because over time they raise the risk of a tumour.
• Scabies, if the itch is also between the fingers, on the wrists and around the navel, and particularly if somebody else at home is scratching too.
• Sexually transmitted infections and genital warts, if there has been unprotected sex and the itch comes with discharge, sores or growths.

A separate case is generalised itching, where the bottom is only one of the places affected. If the whole body itches, the cause lies elsewhere: liver and kidney disease, thyroid problems, iron deficiency, diabetes, blood disorders and side effects of medicines all show up this way.

What must not be missed

See a doctor and let them look, without putting it off, if any of these apply:

• dark blood mixed through the stool, or black tarry motions — that is not piles;
• you can feel or see a lump, a sore, a growth or an area that will not heal;
• your bowel habit has changed: looser or less frequent, a different shape, an urge with no result, going on for several weeks;
• in an adult, the itch has lasted months and responds to nothing;
• you are losing weight without explanation, feel drained or look pale;
• the surrounding skin has turned pale and thin, or conversely hard and thickened;
• the itch began after starting a new medicine.

The point of that list is simple: an itch that drags on in an adult is a reason to be examined, not to apply something. Most of the time what turns up is irritation, piles or a skin condition — but it is precisely among the "just itching" cases that pre-cancerous skin changes, anal cancer and bowel tumours occasionally appear. They are treated far better the earlier they are found, and the examination takes two minutes: for the doctor it is routine, done several times a day.

Seek help the same day, without waiting, if pain beside the anus is building up with swelling and redness and your temperature rises: that is how an abscess starts, and it is drained rather than creamed. Call an ambulance on the single European number 112 if there is heavy bleeding from the back passage and you turn pale, sweaty and faint.

What actually helps

Until the cause is known, the skin needs to be left alone and given room to heal. These are the things that work.

• Wash with warm water and no soap, after opening your bowels and before bed. If you cannot manage without a cleanser, use a mild unscented one and rinse it off completely.
• Do not rub: pat dry with a soft towel or let the skin air-dry. Away from home, wetting ordinary paper beats reaching for a wet wipe.
• Put away the wipes, powders, deodorants, bubble bath, scented paper and every cream nobody prescribed for you.
• Wear loose cotton underwear, change it daily, avoid sitting for hours and avoid overheating.
• Do not scratch — scratching is what keeps the itch alive. Keep your nails short, wear cotton gloves at night, and keep a cool compress by the bed, because cold settles an itch as well as any cream.
• Sort out your bowels: fibre, fluids, and a toilet visit without straining and without long sessions with your phone. If the stool is loose, that is the thing to deal with, or the skin will not heal.
• Look at your diet: in some people coffee, spicy food, citrus, tomatoes, beer and fizzy drinks make the itch noticeably worse. Drop one item at a time rather than half the menu at once.
• Use a barrier: a thin layer of a plain ointment with no active ingredients, on clean dry skin. It keeps the skin away from moisture, and that is the whole purpose.

If two or three weeks of this bring no improvement, there is nothing left to try unaided: you need to be examined. A steroid cream in this area is prescribed by a doctor as a short, deliberate course, because on a fungal infection it makes matters worse and with long use it ruins the skin.

Online consultation

The subject is awkward, and that is exactly why an online consultation suits it: describing an itch is easier than walking into a room with it, and the conversation does most of the work. The Oladoctor doctor will ask when precisely it itches, what your stools look like, what you wash with and what you have already tried — and very often the answer is sitting in those replies. They will explain how threadworms are treated and what to do about everyone else at home, help you tell piles from a fissure, and set out how to handle the skin so the scratching loop is broken. And they will say plainly when talking is not enough: with blood, a lump, a changed bowel habit or an itch of many months, somebody has to look.

This material is for information only and does not replace medical advice.