Oral lichen planus: an update on its pathogenesis.

Oral lichen planus (OLP) is a common T cell-mediated mucocutaneous disease of unknown etiology. A great number of factors have been suggested as relevant to the etiology of this disease. In this article, the authors assemble recent knowledge about the pathogenesis of OLP, discuss some proposed hypotheses, and compare OLP with oral lichenoid lesions.