A 31-year-old woman presents for evaluation of an asymptomatic, firm plaque on the forehead. Lesions of similar size and consistency were present at the nape of the neck and on the chest. The patient was in overall good health.
Key point: It is almost impossible to tell what this is simply by observation! Because of our concern that this might be a cutaneous lymphoma, a biopsy was performed. The latter revealed almost pure sheets of plasma cells in the dermis. Because of this histologic finding, a syphilis serology was obtained; results were positive (RPR 1:256). Thus, this represents an unusual presentation of secondary syphilis. The patient subsequently admitted to casual, unprotected intercourse.
Treatment: Intramuscular benzathine penicillin was given (2.4 million units).
Note: HIV serology is strongly recommended for all new cases of sexually transmitted disease. Also, note that syphilis can present in both typical and highly atypical forms.