Oral lichen planus is a long-term inflammatory condition that affects the lining of the mouth. It is linked to an immune response, but the exact cause is not fully understood. It is not an infection, it is not contagious, and it cannot be passed to another person.
Symptoms and appearance
The condition often causes fine white lines that form a lace-like pattern inside the cheeks. It may also affect the tongue, gums, lips or roof of the mouth. Some people have no discomfort, while others develop red, swollen or ulcerated areas that burn or sting.
Pain may be worse when eating spicy, acidic, salty or very hot food. If the gums are affected, brushing can feel uncomfortable and the gums may look red and shiny.
What can resemble oral lichen planus?
Several conditions can cause white or sore areas in the mouth. These include oral thrush, friction, reactions to medications or dental materials, and other inflammatory disorders. A persistent mouth lesion should be assessed instead of being diagnosed from photographs alone.
Diagnosis
A dentist, doctor or oral medication specialist will examine the mouth and ask about symptoms, medications and general health. A small tissue sample, called a biopsy, is often taken to confirm the diagnosis and exclude another cause. Other tests may be needed when infection or an underlying condition is suspected.
Treatment
Mild oral lichen planus may not need treatment, but regular review is still important. When symptoms interfere with eating, drinking or oral care, treatment may include a corticosteroid gel, ointment, spray or mouth rinse prescribed for use inside the mouth. More severe disease may require specialist treatment.
Use treatment exactly as directed. Corticosteroids in the mouth can increase the chance of thrush, so report new creamy white patches or a change in symptoms. Never stop or change a prescribed medication because it might be contributing to a lichenoid reaction without speaking to the prescriber.
Everyday care
- Brush gently twice a day with a soft toothbrush and keep up regular dental care.
- Choose foods that do not irritate sore areas. Common triggers include chili, citrus fruit, alcohol and very hot drinks.
- Avoid smoking and other tobacco products.
- Ask a dentist about a mild toothpaste if strongly flavored products cause discomfort.
- Keep a note of symptom changes and take prescribed treatments to follow-up appointments.
See our Oral Health guide for more information about caring for the mouth and when to seek dental advice.
Follow up and cancer risk
Most people with oral lichen planus do not develop oral cancer. However, there is a small long-term risk of cancer developing in an affected area. Regular examinations by a dentist or specialist help identify concerning changes early. The need for follow-up depends on the appearance and severity of the condition.
When to seek medical or dental advice
Arrange an assessment for a mouth ulcer, red or white patch, lump, unexplained bleeding, or pain that persists for more than two to three weeks. Seek prompt advice if a known area changes in appearance or becomes harder, thicker or increasingly painful.
Get urgent medical help if swelling causes difficulty breathing or swallowing, or if you cannot drink enough because of severe pain.
Sources
- Mayo Clinic: Oral lichen planus
- Cambridge University Hospitals: Lichen planus of the mouth
- British and Irish Society for Oral Medicine: Oral lichen planus
Using this information
This information supports, but does not replace, an assessment by a qualified healthcare professional. Treatment depends on your symptoms, examination findings and medical history.
Reviewed: 28 August 2026