Why does oral leukoplakia cause a mouth sore that does not heal?

Oral leukoplakia describes a persistent white or grey patch that cannot be explained by simple wiping. Changes in the surface cells can make the area thicker, rougher or more vulnerable to friction from teeth, dentures, tobacco or spicy foods. An ulcer or tender spot may develop beside or within the patch.

A non-healing mouth sore has several possible causes, including trauma, infection and inflammatory conditions. An examination is needed because appearance alone cannot show whether abnormal cells are present.

Book a dental or medical assessment for a sore that persists, returns in the same place, or sits within a white patch. The clinician may inspect the mouth, check nearby teeth or dentures, ask about tobacco and alcohol exposure, and recommend a biopsy if the area needs cell testing.

Avoid picking the sore and reduce avoidable rubbing while waiting. Keep the mouth clean with a soft toothbrush, and mention pain, bleeding, numbness or difficulty eating.

Seek prompt medical or dental care if the sore bleeds repeatedly, becomes harder or larger, causes numbness, affects speech or swallowing, or is accompanied by a neck lump. Seek emergency help for breathing difficulty or inability to swallow fluids.

Ask whether the patch needs a biopsy, what may be irritating it, how to protect the area, and how it will be monitored if no immediate procedure is needed.