Hematoxylin-eosin–stained sections demonstrated a dense lichenoid infiltrate composed almost exclusively of plasma cells. A treponemal immunoperoxidase stain was positive for multiple spirochetal organisms within the epidermis and dermis. Serologic studies revealed a reactive serum rapid plasma reagin test, with a dilution of 1:512, and a positive treponemal antibody-absorption test result. The patient was informed of the diagnosis and refused to undergo testing for human immunodeficiency virus. She returned to the local Department of Health for treatment.