Invasive Fungal Sinusitis in Immunocompromised Hosts

Invasive fungal sinusitis is an uncommon but life-threatening infection. Opportunistic molds, especially Aspergillus and Mucorales species, are the main causes of invasive fungal sinusitis. This entity primarily affects patients who are immunocompromised (e.g., hematologic malignancies, transplant recipients on immunosuppressive medications), or who have uncontrolled diabetes. The mortality is approximately 50%, but varies widely (20-80%). For patients with malignancy as their risk factor, invasive fungal sinusitis can have profound effects on malignancy-related survival by delaying chemotherapy. Limited available interventions, suboptimal early diagnosis, and slow development of new antifungal agents have led to incremental improvements in outcomes. Early use of imaging, rapid institution of appropriate treatment, and a coordinated effort among specialists including infectious disease physicians and otolaryngologists are essential for improved survival. This chapter reviews the risk factors, clinical features, approach to diagnosis, and treatment of invasive fungal sinusitis.