Bone sporotrichosis: 41 cases from a reference hospital in Rio de Janeiro, Brazil

BACKGROUND: Bone sporotrichosis is rare. The metropolitan region of Rio de Janeiro is hyperendemic for zoonotic sporotrichosis and the bone presentations are increasing. METHODS: We studied a retrospective cohort of 41 cases of bone sporotrichosis, diagnosed from 1999–2016. The inclusion criteria was fungal culture isolation from any clinical specimen associated to bone involvement (radiography and/or computed tomography) compatible with fungal osteomyelitis or histopathological findings of bone material compatible with sporotrichosis. Molecular identification was performed when possible. RESULTS: Male patients represented 58.5% of the cases, with a cohort median age of 43 years. Immunosuppressive conditions were present in 68.3% of the patients, mostly HIV coinfection (51.2%). Multifocal bone involvement (more than one anatomical segment) was diagnosed in 61% of the patients, while 39% presented unifocal involvement. The bones of the hands were the most affected (58.5%), followed by the feet (41.5%) and tibia (26.8%). Multifocal group was characterized by a higher proportion of males (p = 0.0045) with immunosuppressive conditions (p = 0.0014). Amphotericin B followed by oral itraconazole was the main treatment, with a median time of 16.7 months (1.5 to 99.2 months), and cure of 53.7% of the patients (84.6% of immunocompetent and 39.3% of immunocompromised patients). Sequelae occurred in 12.2% of the patients—amputations (7.3%) and ankylosis (4.9%), while 22% died in the course of the disease. Sporothrix brasiliensis was the causative agent in all the 9 (22%) performed cases. CONCLUSIONS: Bone sporotrichosis is a chronic, challenging condition with prolonged treatment, often with poor results and sequelae.