Anosmia in COVID-19 patients

Abstract

Abstract Objectives Coronaviruses (CoVs) have a neuroinvasive propensity, and the frequently reported symptoms of smelling and taste dysfunction in many COVID-19 patients may be related to the respective capability of SARS-CoV2, the cause of the current pandemic. In this study we objectified and quantified the magnitude and underreporting of the smelling dysfunction caused by COVID-19 using a standardized test. Methods We conducted a prospective cross-sectional study comparing the proportion of anosmia using Sniffin-sticks in those reporting a loss of smell, in those who did not as well as in uninfected controls. The outcome of anosmic versus not anosmic patients were recorded during hospital stay and at day 15 on a six-category ordinal scale. The study was approved by the institutional review board, all participants consented to the study. Results 40% of 45 consecutive hospitalized COVID-19 patients and 0% of 45 uninfected controls consenting were diagnosed with anosmia. 44% of anosmic and 50% of hyposmic patients did not report having smelling problems. Anosmia or hyposmia was not predictive of a severe COVID-19 manifestation. Conclusions The majority of COVID-19 patients have an objective anosmia and hyposmia, which often occurs unnoticed. These symptoms may be related to the neuroinvasive propensity of SARS-COV-2 and the unusual presentation of COVID-19 disease manifestations.