Calvarial syphilis in an HIV-positive man.

Bone involvement in secondary and tertiary syphilis is a well-documented but unusual phenomenon. We report the case of an atypical presentation of secondary syphilis in a 25-year-old HIV-positive man who has sex with men. He presented initially with headaches and an unusual calvarial swelling. The skull findings were consistent with osteitis and he later developed systemic symptoms. Treponema pallidum serology was positive and the lesions and systemic symptoms resolved completely after administration of appropriate antibiotic therapy.