Can symptoms of anosmia and dysgeusia be diagnostic for COVID‐19?

OBJECTIVE: Olfactory and taste dysfunction (OTD) is a potential neurological manifestation of coronavirus‐2019 (COVID‐19). We aimed to investigate the diagnostic value of symptoms of anosmia and dysgeusia for COVID‐19. METHODS: A comprehensive electronic search was conducted using PubMed, MEDLINE, Scopus, Cochrane database, and Google Scholar from 1 June 2020 to 12 June 2020. All studies reporting symptoms of anosmia and dysgeusia in COVID‐19‐positive patients were included. A total of 23 studies were included in the systematic review. RESULTS: Symptoms of anosmia and dysgeusia were frequently reported by COVID‐19‐positive patients. Symptoms were more common in females and in younger patients. There was no direct association between the severity of COVID‐19 and the presence of symptoms. However, some evidence was found for a longer duration of these symptoms and increased severity of COVID‐19 infection in young patients. CONCLUSION: OTD is commonly reported by COVID‐19 patients. Due to limited literature on the association between OTD and COVID‐19, it is currently not possible to conclude that these symptoms alone can be used to diagnose COVID‐19. However, the presence of OTD can potentially be used as a screening tool for COVID‐19 especially in young and female patients. Further research is required to establish the true diagnostic value of these symptoms and efficacy as screening tools for COVID‐19 patients.