Oral lichen planus. A review.

Lichen planus is a mucocutaneous disease of unknown etiology which, according to current knowledge, may represent a cell-mediated immunological response to induced antigenic changes in the skin and mucosa. Oral lichen planus (OLP) is a disease of adulthood and as one of the most prevalent diseases affecting the oral mucosa it has been the subject of intensive research during recent years. Ultrastructural and immunohistochemical studies particularly dealing with the subepithelial inflammatory cell infiltrate and its relations to epithelial pathology, the basal cell region and the intraepithelial antigen presenting Langerhans' cells, have contributed vastly to our knowledge of the pathogenesis of OLP. However, the treatment of OLP still remains largely symptomatic because many as yet unknown factors, active in the disease process, still remain to be elucidated.