Mouth ulcers: Symptoms, treatment and prevention

Mouth ulcers are sores that appear in the mouth, often on the inside of the cheeks.

Mouth ulcers can be painful when eating, drinking or brushing teeth.

What causes mouth ulcers?

The exact cause of most mouth ulcers is unknown. Stress or tissue injury is thought to be the cause of simple mouth ulcers. Certain foods, including citrus or acidic fruits and vegetables, can trigger a mouth ulcer or make the problem worse. Sometimes a sharp tooth surface or dental appliance, such as braces or ill-fitting dentures, might also trigger mouth ulcers.

Some medications, including common painkillers, beta-blockers and some chest pain medicines may cause a reaction that leads to mouth ulcers.

What are the symptoms of mouth ulcers?

You may have a mouth ulcer if you have:

• A painful sore or sores inside your mouth, on the tongue, soft palate (the back portion of the roof of your mouth), or inside your cheeks.
• Sores in your mouth that are round, white, or grey in colour, with a red edge or border.
• In severe mouth ulcer attacks, you may also experience:
• Fever
• Physical sluggishness
• Swollen lymph nodes

How are mouth ulcers treated?

If sores are large, painful or persistent, your dentist may prescribe an antimicrobial mouth rinse, a corticosteroid ointment, or a prescription or non-prescription solution to reduce the pain and irritation.

Can mouth ulcers be prevented?

Although there is no cure for mouth ulcers and they often reoccur, you may be able to reduce their frequency with good dental hygiene and by:

• Avoiding foods that irritate your mouth, including acidic or spicy foods
• Avoiding irritation from gum chewing
• Brushing with a soft-bristled brush after meals and flossing daily, which will keep your mouth free of foods that might trigger a sore

Seek medical advice about mouth ulcers if you have:

• Unusually large sores
• Sores that are spreading
• Sores that last three weeks or longer
• Intolerable pain despite avoiding trigger foods and taking over-the-counter pain medication
• Difficulty drinking enough fluids
• A high fever with the appearance of the mouth ulcer(s)