Mouth ulcers - also known as canker sores - affect 10-20% of the population and are more common in childhood to early adulthood.

The ulcers are normally small, painful lesions that develop in your mouth or at the base of your gums. They can occur singly or in clusters, and can make eating, drinking, and talking uncomfortable.

Women, adolescents, and people with a family history of mouth ulcers are at higher risk for developing mouth ulcers.

Types of mouth ulcers

There are three types of mouth ulcers: minor, major, and herpetiform.

Minor: Minor mouth ulcers are small oval or round ulcers that heal within 1 to 2 weeks with no scarring.

Major: Major mouth ulcers are larger and deeper than minor ones. They have irregular edges, can take up to 6 weeks to heal and can result in long-term scarring.

Herpetiform: Herpetiform mouth ulcers are pinpoint size, occur in clusters of 10 to 100, and often affect adults. This type of mouth ulcer has irregular edges and will often heal without scarring within 1 to 2 weeks.


There is no definite cause behind mouth ulcers. However, certain factors and triggers have been identified. These include:

  • minor mouth injury from dental work, hard brushing, sports injury, or accidental bite
  • toothpastes and mouth rinses that contain sodium lauryl sulphate
  • food sensitivities to acidic foods like strawberries, citrus, and pineapples, and other trigger foods like chocolate and coffee
  • lack of essential vitamins, especially B12, zinc, folate, and iron
  • allergic response to mouth bacteria
  • dental braces
  • hormonal changes during menstruation
  • emotional stress or lack of sleep
  • bacterial, viral, or fungal infections

Mouth ulcers also can be a sign of conditions that are more serious and require medical treatment, such as: coeliac disease, inflammatory bowel disease and diabetes.


Our pharmacists at Toome Pharmacy are all fully trained to provide you with advice and guidance if you have mouth ulcers, and can also prescribe the appropriate treatment.

If our pharmacist diagnoses mouth ulcers, you will be prescribed hydrocortisone muco-adhesive buccal tablets. You’ll then dissolve one of these tablets in contact with your ulcer 4 times a day for up to 5 days.

During your consultation - which is carried out under the Minor Ailment scheme - our pharmacist will provide you with some guidance as to how to prevent mouth ulcers from recurring. They may, for example, advise you to:

  • Avoid foods that irritate your mouth. Acidic fruits such as oranges or lemon can irritate your mouth just as much as spicy foods!
  • Eat a well-balanced diet and take a daily multivitamin
  • Try to avoid talking while chewing food as this helps to reduce accidental bites.
  • Avoid soft bristle toothbrushes and mouthwashes that contain sodium lauryl sulphate.

Our pharmacist will also advise you as to how to deal with mouth ulcers without medical treatment. If your mouth ulcers do recur, they may suggest that you:

  • Rinse your mouth with warm salt water (without swallowing)
  • Avoid dehydration by drinking adequate fluids
  • Use a straw to drink