Case Report: COVID-19-associated Rhinosinusitis Mucormycosis Caused by Rhizopus arrhizus: A Rare but Potentially Fatal Infection Occurring After Treatment with Corticosteroids.

COVID-19 first emerged in Wuhan, China, in December 2019. Since that time, the frequency of bacterial and fungal coinfections has been continuously increasing. Although invasive pulmonary aspergillosis is being increasingly recognized in association with COVID-19, there is limited information regarding COVID-19-associated mucormycosis. We describe a 50-year-old woman with uncontrolled diabetes who received systemic corticosteroids and remdesevir during her admission for COVID-19. A few days after discharge, the patient was readmitted because of facial swelling and numbness, and a diagnosis of COVID-19-associated rhinosinusitis mucormycosis caused by Rhizopus arrhizus (formerly called Rhizopus oryzae) was confirmed with sequencing of the internal transcribed spacer region of the ribosomal DNA. This report aimed to address the importance of short-term follow-up for COVID-19 patients who have received systemic corticosteroids, particularly those with predisposing conditions, because early detection and prompt, aggressive treatment are essential for the management of invasive fungal infections.