Malignant Syphilis

A 44-year-old man with HIV and intermittent antiretroviral adherence presented with a month-long history of fever and pruritic skin lesions. Examination revealed blackish-brown, lamellated plaques on limbs and scalp. Labs showed CD4 count of 86/mm³, HIV viral load of 35,900 copies/mL, and RPR titer of 1:32. TPPA was positive. Skin biopsy of the forearm revealed diffuse dermal lymphocytes and histiocytes with plasma cells, consistent with malignant syphilis—an uncommon, ulceronodular or crusting manifestation of secondary syphilis seen in immunocompromised patients. The patient declined lumbar puncture and penicillin desensitization due to past anaphylaxis. Treatment with intravenous ceftriaxone for two weeks led to resolution of lesions and fever. At 3 months, the RPR titer had declined to 1:2.

A 44-year-old man with HIV and intermittent antiretroviral adherence presented with a month-long history of fever and pruritic skin lesions. Examination revealed blackish-brown, lamellated plaques on limbs and scalp. Labs showed CD4 count of 86/mm³, HIV viral load of 35,900 copies/mL, and RPR titer of 1:32. TPPA was positive. Skin biopsy of the forearm revealed diffuse dermal lymphocytes and histiocytes with plasma cells, consistent with malignant syphilis—an uncommon, ulceronodular or crusting manifestation of secondary syphilis seen in immunocompromised patients. The patient declined lumbar puncture and penicillin desensitization due to past anaphylaxis. Treatment with intravenous ceftriaxone for two weeks led to resolution of lesions and fever. At 3 months, the RPR titer had declined to 1:2.