Abstract
A 42-year-old otherwise healthy male presented with a 2-month history of a pruritic rash with associated fever, malaise, and arthralgias. One month prior to onset, he received his second COVID-19 vaccination. Examination revealed diffuse erythematous to violaceous scaling and ulcerated papulonodules involving the face, trunk, and extremities with associated left axillary lymphadenopathy. Laboratory workup was remarkable for an elevated RPR 1:256. Punch biopsy revealed dense lymphoplasmacytic infiltrate with granuloma formation. T. pallidum stain was positive, confirming the diagnosis of malignant syphilis. The patient was referred to infectious disease for treatment.
Lues maligna represents an uncommon noduloulcerative variant of secondary syphilis due to an underlying medium-sized vessel vasculitis and is associated with systemic symptoms, usually in an immunocompromised individual. Rarely, lues maligna has been reported in immunocompetent patients, as in this case. Our patient had no history to suggest an immunocompromised state other than recent vaccination. There is evidence that SARS-CoV-2 mRNA vaccination may attenuate innate immunity through various mechanisms, which could explain the development of malignant syphilis in this otherwise healthy male. Furthermore, although granulomas have been well described in tertiary syphilis, it is rare in secondary syphilis. It has been shown that syphilitic nodules of 2-4 month duration are more likely to show granulomatous histology. Potential diagnostic pitfalls of lues maligna include notorious paucity of organisms and negative serologies due to prozone effect. Prior to this, only 2 cases of positive immunohistochemistry in granulomatous secondary syphilis have been reported.