Case report of a man with HIV presenting with malignant syphilis.

Background: Malignant syphilis is a rare manifestation of secondary syphilis and is commonly associated with human immunodeficiency virus coinfection. It can present with multiorgan involvement, which poses a diagnostic dilemma to clinicians.

Methods: We report a case of a middle aged male who presented with near complete vision loss in his right eye with initial concern for fungal endophthalmitis due to his injecting drug use history. He concurrently had right cheek and forearm ulcerative plaques.

Results: He was diagnosed with disseminated syphilis following the punch biopsy of his right cheek, with positive Treponema pallidum result on polymerase chain reaction and identification of spirochaetes on immunostaining from histopathology.

Conclusions: We present the epidemiology of syphilis in Australia and highlight the importance of testing for common sexually transmitted diseases within the emergence of the monkeypox outbreak.