In situ identification of mononuclear cells in lichen planus

In this study, the in situ immunological typing of cell populations in lichen planus was attempted. T lymphocytes and suppressor/cytotoxic subsets, B lymphocytes, macrophages, immunocytes and Langerhans' cells were studied by one or more technical parameters and semiquantitative assessment of T cell populations were carried out. A critical evaluation of assays for T cell characterization was also attempted. T cells were found predominant in lichen planus infiltrate but macrophages were also many. Langerhans' cells were increased in the epidermis compared to normal skin and contact dermatitis.