The cause of oral lichen planus is unknown. T lymphocytes — certain white blood cells involved in inflammation — are normally active at the site of disease or injury and cause the lesions. Doctors and researchers don't know what prompts T lymphocytes to be activated in oral lichen planus. However, in some people, certain factors, such as those below, may trigger an inflammatory disorder.

  • Hepatitis C infection and other types of liver disease
  • Hepatitis B vaccine
  • Allergy-causing agents (allergens), such as foods, dental materials or other substances
  • Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Advil, Motrin IB, others) and naproxen (Aleve, others)
  • Certain medications for heart disease, high blood pressure or arthritis
March 08, 2013