Lichen planus.

Lichen Planus is a relatively common inflammatory dermatosis of unknown origin. The present review summarizes the histological and clinical features of lichen planus and variants, including lichenoid drug reactions, are described. Possible mechanisms of pathogenesis of lichen planus are reviewed. The development of malignancy in association with lichen planus and the association with hepatitis are discussed. Treatment options for the more difficult manifestations of lichen planus are proposed.