Dysgeusia: A review in the context of COVID-19

BACKGROUND: Taste disorders in general, and dysgeusia in particular, are relatively common disorders that may be a sign of a more complex acute or chronic medical condition. During the COVID-19 pandemic, taste disorders have found their way into the realm of general as well as specialty dentistry, with significance in screening for patients who potentially may have the virus. TYPES OF STUDIES REVIEWED: The authors searched electronic databases (PubMed, Embase, Web of Science, Google Scholar) for studies focused on dysgeusia, ageusia, and other taste disorders and their relationship to local and systemic causes. RESULTS: The authors found pertinent literature explaining the normal physiology of taste sensation, proposals for suggested new tastes, presence of gustatory receptors in remote tissues of the body, and etiology and pathophysiology of taste disorders, in addition to the valuable knowledge gained about gustatory disorders in the context of COVID-19. Along with olfactory disorders, taste disorders are one of the earliest suggestive symptoms of COVID-19 infection. CONCLUSIONS: Gustatory disorders are the result of local or systemic etiology or both. Newer taste sensations, such as calcium and fat tastes, have been discovered, as well as taste receptors that are remote from the oropharyngeal area. Literature published during the COVID-19 pandemic to date reinforces the significance of early detection of potential patients with COVID-19 by means of screening for recent-onset taste disorders. PRACTICAL IMPLICATIONS: Timely screening and identification of potential gustatory disorders are paramount for the dental care practitioner to aid in the early diagnosis of COVID-19 and other serious systemic disorders.