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Aphthae, or aphthous ulcers, are common, small, light-coloured, non-contagious sores in the mucous membrane of the mouth. They vary in size from a few millimetres up to two centimetres. In the early phase, depending on the location of the aphtha, the patient may have trouble eating, speaking or with oral hygiene. Aphthae heal spontaneously in 1 to 4 weeks.

There is no clear cause for aphthae. Psychological stress may trigger their appearance, as may deficiency in iron, folic acid or vitamin B. In women, they usually appear at the end of the menstrual cycle. Recurrent aphthae may also be associated with inflammatory bowel disease or coeliac disease. Some foods, such as citrus fruits and tomatoes, may contribute to the appearance of aphthae.


Rinsing your mouth with chlorhexidine solution is recommended during the painful phase. Painkillers may also be used if necessary. There are prescription-free gels and sprays available that may speed up the healing process. Aphthae can also be treated with anti-inflammatory buccal tablets.


As the mechanism of development of aphthae is not completely known, it can be difficult to prevent them from recurring, and there are no completely sure methods of prophylaxis. 

If you have aphthous ulcers often, you should avoid spicy or acidic food. If you are using a toothpaste containing sodium lauryl sulphate, it’s a good idea to try changing it. Toothpastes containing sodium lauryl sulphate, such as many of the basic ones sold in supermarkets, may increase your susceptibility to aphthae. Mild-tasting toothpastes without sodium lauryl sulphate are available from pharmacies.

When should I seek treatment?

The majority of aphthous ulcers heal spontaneously in a couple of weeks. You should seek treatment if your mouth ulcers do not heal in three weeks or if you have trouble eating or speaking. However, there is no established treatment method for aphthous ulcers; they are often best healed with time. 

Information sources: The Finnish Medical Society Duodecim: Terveysportti, Lääkärin tietokanta database

FSHS Dentist / 29 March 2022 

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