The cause of oral lichen planus is unknown. The lesions that appear are the result of inflammation controlled by specific white blood cells called T lymphocytes. Normally, these cells are active at the site of disease or injury.

Doctors and researchers don't know what prompts T lymphocytes to be activated in oral lichen planus. However, certain diseases, medical conditions or other factors may act as triggers of the inflammatory disorder in some people.

WHAT CAUSES LICHEN PLANUS?