Candida tropicalis-Associated Osteomyelitis in an Intravenous Drug User: A Case Report

Candida species represent the most frequent fungal cause of osteomyelitis in patients with a history of drug use, with Candida albicans historically being the predominant pathogen. However, non-albicans Candida species, particularly Candida tropicalis, have emerged as increasingly important pathogens associated with more complex clinical presentations and treatment challenges. Candida tropicalis (C. tropicalis) demonstrates enhanced virulence factors, including superior adherence capabilities and biofilm formation, contributing to its pathogenicity in immunocompromised hosts and those with indwelling foreign materials. We present a case of a 36-year-old man who presented with severe back pain, unrelieved with pain medication (ibuprofen 400mg daily). He endorsed heroin use a month prior, and magnetic resonance imaging (MRI) of the lumbar spine revealed possible osteomyelitis/discitis of the lumbar spine, which required a biopsy of the lumbar spine. Biopsy results later revealed osteomyelitis, with sensitivities positive for C. tropicalis. The patient was discharged home on fluconazole 800 mg daily for six months with follow-up arranged as an outpatient with infectious disease and addiction medicine. This case highlights the diagnostic challenges, treatment considerations, and addiction medicine implications of this uncommon but serious complication of candida infection. This case also underscores the importance of maintaining a high index of suspicion for fungal pathogens in intravenous drug use (IVDU)-related bone and joint infections, particularly when initial bacterial cultures are negative.