Identification of subpopulations of lymphocytes and macrophages in the infiltrate of lichen planus lesions of skin and oral mucosa.

The mononuclear cells of the infiltrate in lichen planus lesions of skin and oral mucosa have been identified by detection of their membrane receptors in frozen-tissue sections. By this method, the infiltrate would appear to consist of predominantly T lymphocytes, some macrophages and only a few B cells. The pathogenesis of lichen planus is discussed in the light of these findings.