Nodular secondary syphilis in three HIV-positive patients: a case series

Nodular secondary syphilis is an uncommon variant of secondary syphilis. We identified three cases of nodular secondary syphilis at our institution. The first patient presented with a diffuse nodular rash that included his scrotum and penis. The second patient had disseminated skin-colored nodules with serosanguinous crust on his face, trunk, and extremities. The third patient had a pruritic papular and nodular rash with overlying crust. All three patients had a reactive rapid plasma reagin and tested positive for fluorescent treponemal antibody absorption. All were eventually confirmed to be human immunodeficiency virus-positive. Histopathological examination demonstrated inflammatory infiltrate in the dermis composed of lymphocytes, histiocytes, and plasma cells, and treponemal staining highlighted spirochetes in the dermis. The patients were successfully treated with intramuscular penicillin benzathine G. Physicians should be aware of nodular syphilis as a less common cutaneous manifestation of secondary syphilis. Prompt diagnosis of secondary syphilis can expedite resolution of the infection and avoid progression to tertiary syphilis.