Epidemiological Characteristics, Pathogenesis and Clinical Implications of Sinusitis in the Era of COVID-19: A Narrative Review.

Sinusitis is a common condition with various forms and different etiologies. In the era of COVID-19, a large number of studies covered the association between sinusitis and COVID-19, while others reported the impact of COVID-19 on the development of acute invasive fungal rhinosinusitis (AIFR), together with the most commonly associated predisposing factors. Fungal sinusitis, particularly AIFR, can be life-threatening. It is important to dissect this association and improve current evidence and management. Therefore, we conducted this literature review to highlight the association between COVID-19 and sinusitis based on evidence from the available studies in the literature. Evidence shows that chronic sinusitis might have a negative impact on COVID-19 outcomes. However, current results are conflicting, and further studies are needed. On the other hand, COVID-19 can also cause olfactory dysfunction, which is usually temporary. In addition, we found several studies that indicated the association between COVID-19 and AIFR. The condition is usually associated with severe morbidities, as affected patients are usually immunocompromised, including those with uncontrolled diabetes, malignancy, immunosuppression, AIDS, the administration of chemotherapy and other immunosuppressive drugs, and COVID-19.