Mouth Ulcers

What are mouth ulcers?

Mouth ulcers are round or oval sores that occur on a break in the mucosa (moist tissue lining) of your mouth.^2,6,7 They are often painful and can make eating, drinking and speaking uncomfortable.^2,8

Typically, you first start getting mouth ulcers in childhood.⁸ You may go on to experience recurrent mouth ulcers which can resolve spontaneously as you get older.⁸ As a result, they are more common in people under the age of 40.⁸ They also occur more frequently in women and in white people than in black people.⁸

 Importantly, mouth ulcers are not the same thing as cold sores (small blisters that develop on the lips or around the mouth).⁶ They do not develop on the skin, and they do not blister.⁷

What are the different types of mouth ulcers?

There are three different types of mouth ulcers:⁸

• Minor ulcers – less than 1 cm in diameter. These heal spontaneously in less than 14 days and account for around 85% of all mouth ulcers
• Major ulcers – usually 1–3 cm in diameter. These are hard and can last from 10 days to six weeks or even longer. They account for around 10% of all mouth ulcers
• Herpetiform aphthous ulcers – very small, grouped lesions. These can persist for seven to 10 days, are extremely painful and account for around 5% of all mouth ulcers. As many as 100 ulcers can be present which may form into larger ulcers

Mouth ulcer symptoms

Mouth ulcers appear on the^:2,6

• Gum
• Cheeks
• Inner lips
• Tongue
• Gum
• Roof of the mouth

They can be white, red, yellow or grey in colour and may cause:^2,6

• Swelling
• Soreness
• Pain that worsens when eating spicy, salty or sour foods

When to seek help

You should go to see a pharmacist for advice and treatment if you have a mouth ulcer.⁶ However, your pharmacist may recommend you see a GP or a dentist if:^5,6

• Your mouth ulcer has lasted three weeks
• You keep getting mouth ulcers
• Your mouth ulcer grows bigger than usual
• Your mouth ulcer is near the back of your throat
• Your mouth ulcer bleeds or becomes more painful or red (as this could be a sign of a bacterial infection)

What causes mouth ulcers?

What causes a mouth ulcer isn’t always clear.^2,4,6 However, most of the time they’re caused by damage to the mucosa in your mouth, for example if you: ^2,4,6

• Accidentally bite the inside of your cheek
• Wear poorly fitting dentures
• Eat hard food
• Have a faulty filling
• Wear braces

If you have recurrent mouth ulcers, they may be triggered by:^2,4,6

• Stress and anxiety
• Hormonal changes during your period
• Sensitivities to certain foods, such as chocolate, spicy foods, coffee, nuts, strawberries, cheese, tomatoes and wheat flour
• Using harsh toothpaste containing sodium lauryl sulphate
• Stopping smoking (when you first stop smoking, you may develop mouth ulcers)
• A diet lacking in vitamin b-12, zinc, folate (folic acid) or iron
• Genetics (40% of people who get recurrent mouth ulcers report they run in their family)

Mouth ulcers can also sometimes be caused by certain medications or treatments, including:⁶

• Non-steroidal anti-inflammatory drugs (nsaids) – such as ibuprofen
• Nicorandil – sometimes used to treat angina (chest pain)
• Beta-blockers – such as propranolol, which is used to treat high blood pressure
• Chemotherapy or radiotherapy – used to treat cancer (this is known as mucositis)

What conditions can mouth ulcers indicate?

Occasionally, mouth ulcers can indicate an underlying medical condition, such as:^2,4,6

• A viral infection – including the herpes simplex virus (HSV), chickenpox, and hand, foot and mouth disease
• Crohn’s disease – a chronic condition that causes inflammation of the digestive tract
• Coeliac disease – a digestive condition caused by a sensitivity to gluten
• Reactive arthritis – which causes inflammation in the body, usually as a reaction to an infection
• HIV/AIDS and lupus – which cause a weakened immune system
• Behçet’s disease – a rare condition that causes inflammation throughout the body

Occasionally, a long-lasting mouth ulcer can be a sign of mouth cancer.⁶ The difference between mouth ulcers and cancer is that the sores caused by mouth cancer won’t heal on their own.^2,6

How to get rid of mouth ulcers

Mouth ulcers don’t always need pharmaceutical treatment, as they should clear up on their own.^5,6 However, there are things you can do to speed up the healing process:^5,6

• Brush your teeth with a soft toothbrush
• Drink cold drinks through a straw
• Get regular check-ups at the dentist
• Try to reduce your stress and anxiety
• Do not use chewing gum
• Avoid using toothpaste containing sodium lauryl sulphate
• Eat a healthy, balanced diet
• Avoid eating rough, crunchy food, like toast or crisps
• Avoid eating spicy, salty or acidic food
• Avoiding drinking very hot or acidic drinks, such as fruit juice

If your mouth ulcer is causing severe pain, is not resolving or may be infected, a pharmacist or GP may recommend:^5,6,9

• Antimicrobial mouthwash (chlorhexidine 0.2%)
• Steroid tablets (hydrocortisone 2.5mg buccal tablets) or mouth spray
• Anaesthetic gel
• Corticosteroid lozenges
• A salt (saline) mouthwash
• Painkilling mouth spray (benzydamine 0.15% oromucosal spray)

Sources

1. https://cks.nice.org.uk/topics/aphthous-ulcer/
2. https://my.clevelandclinic.org/health/diseases/21766-mouth-ulcer
3. https://cks.nice.org.uk/topics/aphthous-ulcer/background-information/prevalence/
4. https://www.mayoclinic.org/diseases-conditions/canker-sore/symptoms-causes/syc-20370615
5. https://www.nhs.uk/conditions/mouth-ulcers/
6. https://www.nhsinform.scot/illnesses-and-conditions/mouth/mouth-ulcer/
7. https://www.royalberkshire.nhs.uk/media/jntjvkfz/mouth-ulcers_may24.pdf
8. https://cks.nice.org.uk/topics/aphthous-ulcer/background-information/definition/
9. https://www.wmic.wales.nhs.uk/wp-content/uploads/2023/07/CAS-PIL-Mouth-Ulcers-v3-20.07.23.pdf