Mycobacterium marinum Infection Leading to HIV Diagnosis: A Case Report.

Non-tuberculous mycobacteriosis (NTM) is a rare infection that can manifest as pulmonary, disseminated, or cutaneous disease. Cutaneous NTM infections are often associated with immunosuppressive conditions, such as HIV infection or exposure to contaminated water, but they can also occur in healthy individuals, complicating the diagnosis. We report the case of a 54-year-old male with a gradually enlarging skin ulcer on his left upper limb. Initial treatment for sporotrichosis failed, and further testing confirmed Mycobacterium marinum infection. The patient had no prior medical history, but due to the persistent nature of the symptoms, HIV testing was performed, revealing advanced HIV infection with a CD4 count of 34 cells/µl. Following appropriate antimicrobial treatment, the ulcer healed, and antiretroviral therapy (ART) was initiated, resulting in a significant improvement in immune function. This case highlights the importance of considering underlying immunosuppressive conditions, such as HIV, when diagnosing persistent cutaneous NTM infections. Early detection and prompt treatment of both M. marinum and HIV were critical in preventing the progression to disseminated disease, which is often fatal in immunocompromised patients.