Epidermal antigens in lichen planus.

The loss of intercellular and basement membrane antigens has been associated with the development of epidermal cell dysplasia and neoplasia. The antigenic components of the epidermis have been investigated in lichen planus, lupus erythematosus and eczema, using pemphigoid and pemphigus sera by the indirect immunofluorescent staining method. In areas of active lichen planus there was extensive reduction or complete absence of basement membrane antigen. Intercellular antigen was preserved in lichen planus although in some damaged rete ridges it appeared to be reduced. Both these antigens were well preserved in lupus erythematosus and eczema. Loss of epithelial antigens is therefore not confined to the development of neoplasia.