A Curious Case of Invasive Fungal Sinusitis in a Post-COVID-19 Patient: A Case Report.

Introduction: Secondary fungal infection following severe acute respiratory syndrome coronavirus 2 is a serious cause of concern as in majority of cases these are associated with devastating consequences. Invasive mucormycosis which was already prevalent in our country came back with a vengeance during the second wave of COVID-19. Methods: A 34-year-old male who had recovered from mild COVID disease developed invasive rhinosinusitis by two different fungi. The patient was followed up for clinical course, diagnosis, treatment, and outcome. Results: This case illustrates a first of a kind of an invasive fungal rhinosinusitis caused by two different fungi: Schizophyllum commune (of phylum Basidiomycota) and Rhizopus arrhizus (of the Mucorales group) in a patient who had recovered from COVID-19. In this case, conventional methods of direct detection and culture only revealed S. commune. Sequencing after DNA extraction from the paraffin blocks was done due to strong clinical suspicion of invasive mucormycosis and R. arrhizus was detected in the tissue sections. Appropriate antifungals for extended duration ensued complete eradication of the infection. Conclusion: Host risk factors are to be taken into consideration while diagnosing fungal infection. One needs to look beyond the obvious when clinical diagnosis is not consistent with the etiological agent isolated and in this regard molecular tools are a great help in establishing the etiological agent conclusively. [ABSTRACT FROM AUTHOR]