Secondary Syphilis with Osteitis

A 32-year-old man with well-controlled HIV presented with a 1-month history of painful forehead nodules. He had engaged in condomless sex with four male partners in the preceding 3 months. Examination revealed two firm, tender nodules on the forehead and a macular torso rash. CT imaging showed subgaleal lesions with lytic bone involvement; bone scintigraphy revealed uptake in the frontal bones, occiput, scapula, and 11th rib. Serologic testing confirmed secondary syphilis (RPR titer 1:32; positive TPPA). Although secondary syphilis typically requires a single dose of penicillin G benzathine, three doses were administered due to concern for osteitis and possible malignancy. Lesions resolved completely, and follow-up bone scans and RPR titers normalized. The case underscores the rare presentation of secondary syphilis with osteitis and the importance of considering syphilis in the differential diagnosis of lytic bone lesions in immunocompromised patients.

A 32-year-old man with well-controlled HIV presented with a 1-month history of painful forehead nodules. He had engaged in condomless sex with four male partners in the preceding 3 months. Examination revealed two firm, tender nodules on the forehead and a macular torso rash. CT imaging showed subgaleal lesions with lytic bone involvement; bone scintigraphy revealed uptake in the frontal bones, occiput, scapula, and 11th rib. Serologic testing confirmed secondary syphilis (RPR titer 1:32; positive TPPA). Although secondary syphilis typically requires a single dose of penicillin G benzathine, three doses were administered due to concern for osteitis and possible malignancy. Lesions resolved completely, and follow-up bone scans and RPR titers normalized. The case underscores the rare presentation of secondary syphilis with osteitis and the importance of considering syphilis in the differential diagnosis of lytic bone lesions in immunocompromised patients.