Oral lichen planus: an update.

Oral lichen planus (OLP) is a chronic autoimmune disease of unknown etiology that affects the skin and mucosae, including the oral cavity. The disease is characterized by lacy, thin white lines on a violaceous background on the oral mucosa, usually on the inside of the cheeks. The disease is also characterized by chronic inflammation and is often associated with severe pain and a burning sensation in the mouth. The etiopathogenesis of lichen planus is complex, with the involvement of T lymphocytes, mast cells, intercellular adhesion molecule-1 (ICAM-1) and major histocompatibility complex class II antigens. The immunologic process results in vacuolar degeneration, lysis of basal cells and, ultimately, liquefaction of the basal cells. The precipitating factors of OLP can be: stress, particular foods, dental plaque, systemic illness and poor oral hygiene. Often no medication is necessary for benign disease. In the case of severe pain and the burning sensation, high potency topical corticosteroids remain the most reliably effective treatment. Other available treatments are topical cyclosporine, tacrolimus, retinoids and other immunosuppressive agents. Systemic corticosteroids may be indicated in patients whose condition is unresponsive to topical corticosteroids. However, OLP remains a challenging disease to treat, in spite of the numerous treatments tried in the patient population.