Mouth ulcers are painful sores that appear in the mouth. Although they’re uncomfortable, they’re usually harmless and most clear up by themselves within a week or two. However, patients with an ulcer of over three weeks’ duration should be referred for biopsy or other investigations to exclude malignancy or other serious conditions such as chronic infections.
What does a mouth ulcer look like?
Mouth ulcers are usually round or oval sores that commonly appear inside the mouth on the cheeks, lips, gums, and tongue. They can be white, red, yellow, or grey in colour and swollen. It is possible to have more than one mouth ulcer at a time and they may spread or grow.
What causes mouth ulcers?
In many cases, the reason for mouth ulcers is unclear. Most single mouth ulcers are caused by damage to the lining inside of the mouth. Examples include accidentally biting the inside of your cheek or a sharp tooth, poorly fitting dentures, hard food, or defective dental filling.
It’s not always clear what causes mouth ulcers that keep returning, but triggers are thought to include:
- Stress and anxiety
- Hormonal changes – Some women develop mouth ulcers during their monthly period.
- Eating certain foods – such as spicy foods, coffee, peanuts, almonds, strawberries, cheese, tomatoes, and wheat flour.
- Toothpaste containing sodium lauryl sulphate
- Smoking cessation – When you first stop smoking, studies have shown formation of mouth ulcers.
- Genetic factors – Around 40% of people who keep getting mouth ulcers report that it runs in their family.
Mouth ulcers can sometimes be caused by certain medical conditions, such as:
- Viral infections – including the cold sore virus, chickenpox, and hand, foot, and mouth disease.
- Vitamin B12 or iron deficiency
- Crohn’s disease – a long-term condition that causes inflammation of the lining of the digestive system.
- Coeliac disease – a common digestive condition where a person has an adverse reaction to gluten.
- Reactive arthritis – a condition that causes inflammation in various places in the body, usually as a reaction to an infection.
- Weakened immune system – for example, due to HIV or lupus.
- Behçet’s disease – a rare and poorly understood condition that also causes swelling of the blood vessels.
Mouth ulcers can sometimes be caused by certain medications or treatments, such as:
- Non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen.
- Nicorandil – a medication sometimes used to treat angina.
- Beta-blockers – used to treat conditions such as angina, high blood pressure, and abnormal heart rhythms.
- A side effect of chemotherapy or radiotherapy – this is known as mucositis.
How to treat mouth ulcers
Mouth ulcers don’t usually need to be treated, because they tend to clear up by themselves within a week or two. However, treatment can help reduce swelling and ease any discomfort. This may help if you keep getting mouth ulcers or the mouth ulcer affects your eating and drinking.
Mouth ulcers shouldn’t be confused with cold sores, which are small blisters that develop on the lips or around the mouth. Cold sores often begin with a tingling, itching, or burning sensation around your mouth.
Self-care
These are things you can do to avoid mouth ulcers or speed up healing.
- Apply a protective paste recommended by your pharmacist.
- Use a soft toothbrush to brush your teeth.
- Use toothpaste that does not contain sodium lauryl sulphate as it may cause irritation.
- Avoid hard, spicy, salty, acidic, or hot food and drink until the ulcer heals.
- Use a straw to drink cool beverages.
- Avoid things that may trigger your mouth ulcers.
Medicine from your pharmacist
You can get several types of mouth ulcer treatment from a pharmacy. Speak to your pharmacist about the best treatment for you. Options include the following:
- Antimicrobial mouthwash may speed up healing and prevent infection of the ulcer. Children under two shouldn’t use this treatment. It also contains chlorhexidine gluconate, which may stain teeth – but this may fade once treatment is finished.
- Painkillers are available as a mouthwash, lozenge, gel, or spray. They can sting on first use and your mouth may feel numb – but this is temporary. Mouthwash can be diluted with water if stinging continues. Children under 12 shouldn’t use mouthwash or gel. This type of mouthwash shouldn’t be used for more than seven days in a row.
- Corticosteroid lozenges may reduce pain and speed up healing. These are best used as soon as the ulcer appears but shouldn’t be used by children under 12.Corticosteroid lozenges may reduce pain and speed up healing. These are best used as soon as the ulcer appears but shouldn’t be used by children under 12.
Medicines from your dentist or doctor
If necessary, you may be prescribed a course of stronger corticosteroids to help reduce pain and swelling and speed up healing. Corticosteroids are available on prescription as tablets, mouthwash, paste or spray, but are not suitable for children under 12.
If you notice persistent mouth ulcers that do not heal for several weeks, consult your dentist or doctor.
