Sinonasal pathophysiology of SARS‐CoV ‐2 and COVID ‐19: A systematic review of the current evidence Isabelle Gengler MD James C. Wang MD, PhD Marlene M. Speth MD, MA Ahmad R. Sedaghat MD, PhD First published:10 April 2020 https://doi.org/10.1002/lio2.384 Citations: 1 SECTIONS PDF TOOLS SHARE Abstract Objective The ongoing pandemic of coronavirus disease (2019 coronavirus disease [COVID‐19]), caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS‐CoV‐2) virus, is highly contagious with high morbidity and mortality. The role of the nasal and paranasal sinus cavities is increasingly recognized for COVID‐19 symptomatology and transmission. We therefore conducted a systematic review, synthesizing existing scientific evidence about sinonasal pathophysiology in COVID‐19. Study Design Systematic review. Methods Systematic searches were performed of all indexed studies in PubMed/Medline and Cochrane databases through 28 March 2020 and studies searchable on preprints.com (including ArXiv and Scilit repositories) through 30 March 2020. Data extraction focused on sinonasal pathophysiology in COVID‐19. Results A total of 19 studies were identified. The sinonasal cavity may be a major site of infection by SARS‐CoV‐2, where susceptibility genes required for infection are expressed at high levels and may be modulated by environmental and host factors. Viral shedding appears to be highest from the nose, therefore reflecting a major source for transmission. This has been highlighted by multiple reports of health care‐associated infection (HAI) during rhinologic procedures, which are now consequently considered to be high risk for SARS‐CoV‐2 transmission to health care workers. While sinonasal symptomatology, such as rhinorrhea or congestion, appears to be a rarer symptom of COVID‐19, anosmia without nasal obstruction is reported as highly specific predictor of COVID‐19+ patients. Conclusion Sinonasal pathophysiology is increasingly important in our understanding of COVID‐19. The sinonasal tract may be an important site of infection while sinonasal viral shedding may be an important transmission mechanism—including HAI. Anosmia without nasal obstruction may be a highly specific indicator of COVID‐19. Level of Evidence 2a. 1 INTRODUCTION The 2019 coronavirus disease (COVID‐19) was first identified in December 2019 in Wuhan, China and subsequently found to be caused by a novel coronavirus, now referred to as Severe Acute Respiratory Syndrome Coronavirus 2 (SARS‐CoV‐2).1, 2 SARS‐CoV‐2 is highly infectious, with an estimated basic reproduction number in the range of 2 to 3—indicating that on average one infected person will infect 2 to 3 others.3 To date, SARS‐CoV‐2 is confirmed to have infected over 1 million individuals worldwide and killed over 50 000. COVID‐19 consists of upper and lower respiratory tract components of the SARS‐CoV‐2 infection.1, 4 Mortality associated with SARS‐CoV‐2 is due to lower respiratory tract manifestations of the disease, such as severe acute respiratory distress syndrome. This is similar to outbreaks of other coronaviruses including SARS‐CoV‐1 in 2003 and the middle east respiratory syndrome coronavirus (MERS‐CoV) in 2012.5 However, as the COVID‐19 pandemic has spread and our knowledge about it grown, sinonasal pathophysiology has been uniquely brought to the forefront with important roles in infection, transmission, and pathognomonic symptomatology that may identify infected individuals. Given the extreme morbidity that is associated with COVID‐19 and the fact that the world's attention is entrained on this disease, many anecdotal reports are disseminated through conventional or social media without the provision of detailed scientific methodology or the performance of a scientific review. Although our understanding of COVID‐19 continues to rapidly evolve, there are already clinically informative insights with respect to sinonasal pathophysiology that have been uncovered in the scientific literature. The objective of this systematic review was to synthesize existing scientific evidence on the role of sinonasal pathophysiology in COVID‐19.
