Aphthous Mouth Ulcers

Aphthous mouth ulcers are painful, and recur from time to time. Each bout of ulcer(s) goes without treatment. Mouthwashes and lozenges may ease the pain, and may help the ulcers to heal more quickly.


What are aphthous mouth ulcers?

Aphthous mouth ulcers are painful sores that can occur anywhere inside the mouth. They are the most common type of mouth ulcer. At least 1 in 5 people develop aphthous mouth ulcers at some stage in their life. Women are affected more often than men.

There are three types:

  • Minor aphthous ulcers are the most common (8 in 10 cases). They are small, round, or oval, and are less than 10 mm across. They look pale yellow, but the area around them may look swollen and red. Only one ulcer may develop, but up to five may appear at the same time. Each ulcer lasts 7-10 days, and then goes without leaving a scar. They are not usually very painful.
  • Major aphthous ulcers occur in about 1 in 10 cases. These are 10 mm or larger. Usually only one or two appear at a time. Each ulcer lasts from two weeks to several months, and then goes but leaves a scar. They can be very painful - eating may become difficult.
  • Pinpoint aphthous ulcers occur in about 1 in 10 cases. These are tiny, about 1-2 mm across. Many occur at the same time, but some may join together and form irregular shapes. Each ulcer lasts one week to two months. (These are sometimes called 'herpetiform ulcers', but they have nothing to do with herpes or the herpes virus.)

Aphthous ulcers usually first occur between the ages of 10 and 40. They then recur from time to time. There can be days, weeks, months, or years between each bout of ulcers. The ulcers tend to recur less often as you become older. In many cases, they eventually stop coming back. Some people feel a burning in part(s) of the mouth for a day or so before an ulcer appears.

What causes aphthous mouth ulcers?

The cause is not known. They are not infectious, and you cannot 'catch' aphthous mouth ulcers.

  • In most cases, the ulcers develop for no apparent reason in people who are healthy.
  • In some cases, the ulcers are related to other factors or diseases. These include:
    • Injury - such as badly fitting dentures, a graze from a harsh toothbrush, etc.
    • Changes in hormone levels. Some women find that mouth ulcers occur just before their period. In some women, the ulcers only develop after the menopause.
    • Some ex-smokers find they develop ulcers only after stopping smoking.
    • A lack of iron, or a lack of certain vitamins (such as Vitamin B12 and Folic acid) may be a factor in some cases.
    • Rarely, a food allergy may be the cause.
    • Mouth ulcers run in some families. So, a genetic factor may play a part in some cases.
    • Stress or anxiety is said to trigger aphthous mouth ulcers in some people.
    • A reaction to a medication is a rare cause. For example, Nicorandil, anti-inflammatory drugs, and oral nicotine replacement therapy have been reported to cause mouth ulcers in some people.
    • Mouth ulcers are more common in people with Crohn's disease, coeliac disease, HIV infection, and Bechet's disease. But the ulcers may not be aphthous type.

Tell your doctor if you have any other symptoms in addition to the mouth ulcers. Sometimes a blood sample or other tests are advised if any of the above conditions are suspected.

What are the treatments for aphthous ulcers?

Treatment aims to ease the pain when ulcers occur, and to help them to heal as quickly as possible. (There is no treatment that prevents aphthous mouth ulcers from recurring.)

  • No treatment may be needed. The pain is often mild, particularly with the common 'minor' type of aphthous ulcer. Each bout of ulcers will go without treatment.
  • General measures include:
    • Avoid spicy foods, acidic fruit drinks, and very salty foods (such as crisps) which can make the pain worse.
    • Use a straw to drink, to by-pass ulcers in the front of the mouth. (Note: do not drink hot drinks with a straw, as you may burn your throat. Only cold drinks.)
    • Use a very soft toothbrush. See a dentist if you have badly fitting dentures.
    • If you suspect a medication is causing the ulcers, then a change may be possible. For example, if you are using oral nicotine replacement therapy (nicotine gum or lozenges), it may help to use a different type instead such as patches or nasal spray.
  • Chlorhexidine mouthwash may reduce the pain. It may also help ulcers to heal more quickly. It also helps to prevent ulcers from becoming infected. Chlorhexidine mouthwash is usually used twice a day. It may stain teeth brown if you use it regularly. However, the stain is not usually permanent, and can be reduced by avoiding drinks that contain tannin (such as tea, coffee, or red wine), and by brushing teeth before use. Rinse your mouth well after you brush your teeth as some ingredients in toothpaste can inactivate chlorhexidine.
  • Steroid lozenges may also reduce the pain, and may help ulcers to heal more quickly. By using your tongue you can keep a lozenge in contact with an ulcer until the lozenge dissolves. A steroid lozenge works best the sooner it is started once an ulcer erupts. If used early, it may 'nip it in the bud', and prevent an ulcer from fully erupting. The usual dose is one lozenge, four times a day, until the ulcer goes. In children, use for no more than five days at a time.
  • Steroid paste (gel) is an alternative to a lozenge.
  • A painkilling oral rinse, gel, or mouth spray may help to ease pain. For example, benzydamine spray, or choline salicylate gel. However, the effect of each dose does not last very long.

You can buy all the treatments listed above from pharmacies without a prescription. Ask your pharmacist for advice as they come in various brand names.

Other treatments may be tried if the above do not help or where the pain and ulceration are severe. For example, a course of steroid tablets, strong steroid mouthwashes, colchicine, tetracycline or doxycycline mouthwashes, and some immunosuppressant drugs.

When should I see a doctor?

Aphthous mouth ulcers can be painful, are often a nuisance, but are not serious. But remember, not all mouth ulcers are aphthous ulcers. Other types of ulcer can occur in the mouth. Also, cancer of the mouth may sometimes first seem like a mouth ulcer.

Therefore, see a doctor or dentist if a mouth ulcer lasts more than 2-3 weeks. Particularly if it does not appear to be like those described above, or shows no sign of healing or going