2Department of History of Medicine and Ethics, Erciyes University Faculty of Medicine, Kayseri, Turkey
3Department of Radiology, Erciyes University Faculty of Medicine, Kayseri, Turkey
4Department of Cardiology, Wake Forest University School of Medicine, North Carolina, USA
5Laboratory Medicine Marshfield Clinic Laboratories, Wisconsin, USA
Abstract
The term “sign” has been used to describe various phenomena observed in patients with coronavirus disease 2019 (COVID-19). Discrepancies in the use of this term have been identified when it is used in context with COVID-19. The goals of this review are to provide an overview, describe signs, and clarify misconceptions regarding the use of these terms in COVID-19 patients. PubMed and Medline databases were searched using individual and Medical Subject Headings (MeSH) terms, including coronavirus, COVID-19, and sign, in human studies within the English literature published from inception to December 31, 2020. Studies where the word “sign” was used in a context different from that for COVID-19 (e.g., sentinel sign) were excluded. Three hundred fifty-seven studies were potentially identified and after applying the exclusion criteria and further adjudication, 92 studies constituted the final data set. The majority of signs found in the COVID-19 literature have been applied and aptly described primarily in radiologic diseases of the chest. The term “sign,” in other situations, is often misappropriated as it actually represents a physical finding rather than a sign. A total of 27 radiologic signs have been identified on chest computed tomography (CT) or high-resolution CT (HRCT), and 18 cutaneous signs (or findings) have been observed during the physical examination in COVID-19. Signs lack sufficient sensitivity or specificity by themselves; however, in the appropriate clinical setting, they should raise clinical suspicion for this infectious disease.