Erythema dyschromicum perstans: immunopathologic studies

Immunopathologic studies of a patient with clinical and histologic evidence of erythema dyschromicum perstans revealed Ia antigen expression on epidermal keratinocytes, pronounced OKT4 and OKT6 staining of epidermal dendritic cells, and dermal infiltration of T lymphocytes of both helper-inducer (OKT4) and suppressor-cytotoxic (OKT8) phenotypes--a pattern commonly associated with lichen planus. These findings, taken in conjunction with positive IgG staining on colloid bodies, suggest the possibility that erythema dyschromicum perstans and lichen planus have similar disease processes.