Post-Transplant Opportunistic Infection: Case of Mycobacterium Haemophilum Masquerading as Leprosy in a Renal Transplant Patient.

Introduction Immunosuppression following solid organ transplantation (SOT) predisposes patients to the development of opportunistic infections that manifest in many ways including cutaneous infection. Skin lesions in immunosuppressed patients have a broad differential including both infectious and non-infectious etiologies. Skin infections by mycobacteria are relatively rare and most are due to nontuberculous mycobacterium (NTM). One such NTM, Mycobacterium haemophilum, is generally reported in opportunistic skin infections often associated with water exposure. Very rarely, M. leprae also has been reported as a cause of opportunistic skin infections in SOT recipients. Both pathogens may be difficult to distinguish both clinically and pathologically, but culture can distinguish between the two because M. haemophilum will grow and M. leprae will not. We present a case of M. haemophilum cutaneous infection in a renal transplant recipient that was initially felt to be due to M. leprae based on biopsy appearance.