Mouth ulcers
A mouth ulcer is a break in the lining of the mouth: a patch where the surface layer has come away and the tissue beneath is exposed.
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Medicines commonly prescribed for Mouth ulcers
For informational purposes only. Always consult a doctor before using any medicine.
Dosage form: CREAM, 1 mgActive substance: betamethasoneManufacturer: Galenicum Derma S.L.U.Prescription requiredDosage form: CREAM, 64 mg betamethasone dipropionate / 100 gActive substance: betamethasoneManufacturer: Organon Salud S.L.Prescription requiredDosage form: OINTMENT, 64 mg betamethasone dipropionate / 100 gActive substance: betamethasoneManufacturer: Organon Salud S.L.Prescription required
A mouth ulcer is a break in the lining of the mouth: a patch where the surface layer has come away and the tissue beneath is exposed. The common recurring kind are called aphthous ulcers, or canker sores, and repeated crops go by the name of aphthous stomatitis. They are thoroughly ordinary: almost everyone has bitten a cheek or scalded a mouth on tea, and about one person in five gets them regularly. The pain is often out of all proportion to the size, since a tiny ulcer on the tongue can ruin a week. Nearly always they are harmless and heal by themselves. It is not they that are dangerous but the exceptions, and this page is essentially about telling the two apart.
What they look like and what they are mistaken for
A typical aphthous ulcer is a round or oval crater up to five to seven millimetres across, with a greyish or yellowish base and a bright red rim around it. It appears on the loose lining: the inside of the lip and cheek, under the tongue, along the side of the tongue, at the base of the gum. It heals in one to two weeks and leaves no mark.
There are other patterns. A large ulcer of more than a centimetre, deep, with raised edges, takes several weeks and may leave a scar. And the opposite picture: ten or more pinpoint ulcers that merge into one painful patch.
Aphthous ulcers are most often confused with cold sores, and the two are quite different. A cold sore sits at the border of the lip and skin, starts with itching and tingling, goes through a blister stage and is infectious. An aphthous ulcer appears inside the mouth, produces no blisters and is passed on neither by a kiss nor by sharing a cup. The distinction matters: antiviral treatment works on cold sores and does nothing at all for aphthous ulcers.
A first-ever encounter with the herpes virus is a separate matter and happens mostly in children: dozens of small ulcers appear in the mouth at once, the gums are red and bleed and there is a fever. That is not aphthous stomatitis and is treated differently.
Why a single ulcer appears
More than half of cases are plain injury, and the cause can usually be recalled without help.
- a cheek, lip or tongue bitten while eating or talking;
- the sharp edge of a chipped tooth, an old filling, a brace or a poorly fitting denture;
- a burn from hot food or drink;
- a scratch from a hard toothbrush, a fish bone, a rusk or crisps;
- damage after dental treatment.
An ulcer of this kind is tied to one place: it sits exactly where something rubs or where you bit. Remove the cause — smooth the sharp edge, adjust the denture — and it heals and does not come back. If the cause stays, the ulcer will persist for weeks, and that in itself is a reason to be seen.
Some things do not tear the lining themselves but leave it more vulnerable: toothpaste containing sodium lauryl sulfate, very acidic and very salty food, lack of sleep, stress, and the weeks after flu or tonsillitis.
When ulcers keep coming back
If ulcers appear several times a year, or barely clear at all, the cause is no longer an accidental bite. At that point it is worth looking, because what turns up is often something that can be put right.
The first thing checked is deficiency. A shortage of iron, vitamin B12, folate, zinc or vitamin D often shows itself precisely as recurrent ulcers, sometimes long before any anaemia. A simple blood test settles it, and correcting the deficiency frequently stops the crops altogether.
The second is hormonal and everyday circumstance: in some women ulcers turn up on particular days of the cycle, and in many people during periods of heavy stress and short sleep. People who have just given up smoking often go through several months of worse ulcers; this is temporary and settles on its own.
The third is medicines. Anti-inflammatory painkillers, some blood pressure drugs, nicorandil, methotrexate and a number of others can cause them. If the crops began soon after a new prescription, it is worth raising with the prescriber — but not stopping the drug on your own.
The fourth is conditions for which mouth ulcers are one of the earliest signs: coeliac disease, Crohn's disease and ulcerative colitis, oral lichen planus, and states of reduced immunity. Behçet's disease stands apart: in it mouth ulcers go together with genital ulcers, inflamed eyes, nodules and rashes on the skin and joint pain. That combination should be spelled out to a doctor directly — left unmentioned it takes a long time to find, and prompted it is recognised quickly.
What helps at home
There is no quick way to heal an ulcer. There are ways to reduce the pain and stop getting in the way of healing, and that is usually enough.
Worth doing:
- rinse with warm salt water: half a teaspoon of salt in a glass of warm water, rinse and spit it out, do not swallow;
- switch to a soft toothbrush and a toothpaste without sodium lauryl sulfate;
- eat soft, cool food — yoghurt, soft cheese, soup at room temperature, porridge;
- drink cold drinks through a straw, past the sore spot;
- have the sharp edge that started it all smoothed or covered — that is a job for a dentist, and it is the single most useful thing to do about a traumatic ulcer.
Best avoided until it heals: spicy, salty and sour food, tomatoes and citrus, nuts, crisps, rusks and crusts, very hot tea, and spirits. Do not worry at the ulcer with the tongue or try to cauterise it with alcohol, bicarbonate or garlic — that only draws healing out.
What a pharmacy can offer without a prescription
Pharmacy products do not speed up healing in themselves, but they make the few days while an ulcer hurts appreciably easier.
- Pain-relieving gels and sprays for the lining — either with a local anaesthetic or with an anti-inflammatory action. Applied before meals. Salicylate gels are not used in children.
- Antiseptic mouthwashes, including chlorhexidine: they do not heal anything but reduce the chance of infection setting in. Prolonged use stains the teeth, so courses are kept short.
- Protective pastes and films that cover the ulcer against food and friction — a simple and underrated measure.
- Corticosteroid lozenges — tablets that are not swallowed but held against the ulcer to dissolve. In most countries these are prescription-only, so ask the pharmacist what is available.
- Painkillers by mouth if the pain is interfering with eating and sleeping. Paracetamol is the simplest. Ibuprofen and other anti-inflammatory painkillers also work, but they do not suit people with peptic ulcer disease or a tendency to stomach bleeding, kidney disease, poorly controlled blood pressure or those on anticoagulants, and in the second half of pregnancy they are not taken at all.
What a doctor or dentist can prescribe
When ulcers are severe, frequent or will not heal, treatment moves beyond the pharmacy shelf.
Usually that means topical corticosteroids in various forms: ointments and gels on an adhesive base, a mouthwash made up from a soluble tablet, lozenges. They are given in short courses and, used properly, act only where they are applied.
Alongside that, the doctor looks for the cause and deals with it: blood tests for deficiencies and markers of inflammation, a check for coeliac disease, a referral to a dentist to smooth a sharp edge and rework a denture, or to a gastroenterologist or rheumatologist if the picture points to a systemic disease. Sometimes a drug that has caused the ulcers is changed.
For very severe aphthous stomatitis that does not respond to topical treatment, medicines taken by mouth to damp down inflammation are used. That is specialist territory, and they are prescribed with regular blood monitoring.
When you must see someone
One rule matters above all: an ulcer that has not healed in three weeks needs to be looked at. A mouth ulcer that will not heal is one of the first signs of mouth cancer, and caught in time that responds well to treatment. There is nothing to be gained by waiting longer.
Do not put the visit off in other situations either:
- the ulcer is not like the previous ones: bigger, firmer to the touch, with raised edges, on the side of the tongue or further back towards the throat;
- a white or red patch that will not wipe off, or a lump, has appeared next to it;
- the ulcer bleeds, hurts more and more, or redness and swelling are spreading around it;
- ulcers recur more than a few times a year, or barely clear;
- there are also genital ulcers, inflamed eyes, painful swollen joints or a rash;
- the ulcers began soon after starting a new medicine;
- you are losing weight, or have persistent tiredness, night sweats or enlarged glands in the neck.
Call an ambulance straight away (in Spain, Italy, Portugal, Poland and Ukraine the single European number is 112) if:
- the mouth ulcers come with a high temperature together with sore eyes, reddening and peeling of the skin — that is how a severe drug reaction begins;
- breathing has become difficult, or swallowing even saliva has;
- mouth ulcers and fever appear in someone taking chemotherapy, methotrexate, clozapine or medicines for the thyroid — an urgent blood count is needed, because the cause may be a sharp fall in the white cell count;
- a child is refusing to drink because of the pain, has dry lips and tongue, is listless and has not passed urine for a long time.
Online consultation
Mouth ulcers are exactly the sort of problem where a remote appointment does almost everything that is needed. What the doctor needs is the account and a photograph, not touch: where exactly, for how many days, first time or umpteenth, what was eaten and drunk, what medicines have been started, and whether anything is going on beyond the mouth.
From that, several things get settled in one go: whether this is an aphthous ulcer, an injury or something else; whether blood tests for iron, B12, folate and coeliac disease are called for; which preparation suits given age, pregnancy and other medicines; and exactly when to stop waiting and go to be examined. Recurrent cases are worth their own discussion — going calmly through a year of history often yields more than looking at one ulcer.
The limits are worth naming honestly. Feeling a lump, checking the glands in the neck and above all taking a biopsy cannot be done through a screen, so an ulcer older than three weeks, any lump and any patch that will not heal will be sent for examination in person. And with a high temperature affecting the eyes and skin, or with difficulty breathing or swallowing, what is needed is an ambulance rather than an appointment.
This material is for information only and does not replace medical advice.
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