Rare Invasive Fusarium Sinusitis in a Transiently Immunosuppressed Patient

A Florida cattle rancher undergoing treatment for lumbar osteomyelitis presented with severe neutropenia and febrile episodes after being discharged on a seven-week course of intravenous (IV) vancomycin and cefepime. Upon admission, antibiotics were changed, and micafungin and filgrastim were added. Several days later, he had a normalizing absolute neutrophil count (ANC) and improving fevers with an overall good clinical appearance. Discharge seemed near, but he continued to complain of nasal congestion and mild oromaxillary pain. In caution, a CT maxillofacial scan and ENT evaluation were performed that revealed extensive nasal septal necrosis with cultures growing Fusarium suttonianum, prompting treatment with IV liposomal amphotericin, IV voriconazole, and oral terbinafine. Due to reported resistance to FDA-approved antifungals, compassionate use medications were explored. Clinically, he continued to look well and reported minimal symptoms despite the severity of necrosis. The patient responded well to triple antifungal therapy inpatient and continued therapy at home until antifungals were paused due to amphotericin-induced acute kidney injury. He had completed 38/42 days of planned treatment at this point, so the decision was made to hold antifungals (including potential compassionate use medications) until his upcoming ENT debridement. This ENT evaluation then confirmed no residual disease. Continuation of the antifungal regimen and additional compassionate use medications were not pursued, and the patient continued to do well. This case teaches to take the potential hematological complications of many antibiotics seriously and raises further teaching points to consider on the risks and management of rare, rapidly progressing invasive infections such as Fusarium.