Patient information · General health
Mouth ulcers
and the three-week rule that matters
Most mouth ulcers are harmless, caused by minor trauma or stress, and heal within a fortnight. Two situations are different: an ulcer that will not heal, and ulcers that keep returning. The first needs urgent assessment; the second usually has a findable and treatable cause.
Seek urgent assessment for
- an ulcer lasting more than three weeks — this needs urgent referral
- an ulcer that is painless, hard, or has raised rolled edges
- a red or white patch in the mouth that does not rub off
- an unexplained lump in the mouth or neck, or a loose tooth with no dental cause
- difficulty or pain swallowing, or a persistently hoarse voice
- ulcers with fever, rash, or eye or genital ulcers
A single non-healing ulcer is the commonest presentation of mouth cancer, and painlessness is a warning rather than a reassurance. Risk is higher with smoking, chewing tobacco or paan, betel quid, and heavy alcohol — all of which are relatively common in East London. Three weeks is the threshold for urgent referral.
The common kind
Aphthous ulcers are round or oval, with a white, yellow or grey base and a red border, and they hurt out of all proportion to their size. Most are minor — under 1cm, healing in 7 to 14 days without scarring. A minority are major — larger, deeper, lasting weeks and sometimes scarring.
What causes recurrent ulcers
- Deficiencies — iron, ferritin, B12, folate and vitamin D. These are the single most useful thing to test and are found surprisingly often.
- Coeliac disease — recurrent mouth ulcers can be the only obvious feature.
- Trauma — a sharp tooth, ill-fitting denture, brace, or biting the cheek.
- Sodium lauryl sulfate in toothpaste, which triggers ulcers in some people. Switching to an SLS-free toothpaste is free and works for a proportion.
- Stress, hormonal changes and stopping smoking.
- Inflammatory bowel disease, Behçet's disease, and some medicines including nicorandil and anti-inflammatories.
- Immunosuppression, including HIV.
What helps
- Antimicrobial mouthwash — chlorhexidine — reduces secondary infection and speeds healing.
- Topical anaesthetic gels or sprays for pain, particularly before eating.
- Topical corticosteroid preparations, which reduce severity and duration and are prescribed for troublesome recurrent ulcers.
- Warm salt water rinses, several times a day.
- Avoid acidic, salty, spicy and rough foods; use a soft toothbrush and a straw for drinks.
- Correct any deficiency found — this alone stops recurrent ulcers in a meaningful proportion of people.
Toothpaste is worth a two-month trial
Sodium lauryl sulfate is the foaming agent in most toothpastes and is a recognised trigger for recurrent aphthous ulceration. Several small studies show fewer and less painful ulcers on switching. SLS-free toothpaste is widely available and inexpensive, and two months is enough to know whether it makes a difference for you. It costs nothing to try and helps a reasonable number of people.
Reducing your risk of mouth cancer
- Stop smoking, and stop chewing tobacco, paan, betel quid or gutka — all substantially raise risk, including without tobacco.
- Keep alcohol within recommended limits; alcohol and tobacco together multiply the risk rather than adding to it.
- See a dentist regularly — dentists detect a significant proportion of mouth cancers.
- HPV vaccination reduces the risk of some throat cancers.
- Check your own mouth monthly: lips, gums, tongue including underneath, and inside the cheeks.
Why come to us. An ulcer lasting more than three weeks needs seeing quickly, and we can see you the same day, seven days a week. For recurrent ulcers we test the things that actually explain them — ferritin, B12, folate, vitamin D and coeliac screening, all in-house — with results explained face to face rather than a message telling you they are normal. We prescribe topical treatment, and refer urgently to maxillofacial or ENT services where anything needs excluding.
Seen the same day; the causes actually tested
Ferritin, B12, folate and coeliac screening in-house. Seven days a week.
Tower Bridge Hospital London
97–99 Whitechapel Road, London E1 1DT
WhatsApp 07903 284 189
info@mhwclinic.co.uk
Open Mon–Sat, 9am–7pm (closed Sundays until September)
In an emergency
Call 999, or go to the Royal London Hospital Emergency Department, Whitechapel Road, London E1 1FR.
When we are closed and it is not an emergency
Call NHS 111 or visit 111.nhs.uk.