Dysosmia and dysgeusia as differential diagnostics for clinical triaging of COVID-19 cases

Smell and taste disorders are recognized as frequent, and often the only, signs occurring in the early phase of SARS-Cov-2 infection and in many cases perdure as post-viral symptoms. This evidence raised a general reconsideration of chemosensory deficits, further suggesting that their appearance can be considered as a discriminative and predictive tool to detect COVID-19 cases. In this study, encompassing the first and second pandemic wave, participants estimated their olfactory and gustatory sensitivity, plus they were administered the validated Brief Smell Identification Test (BSIT). We observed that smell and taste impairments were mainly experienced by COVID-19-positive subjects with comparable severity of respiratory symptoms as non-COVID-19 patients. In addition, we noticed that the diagnostic power of subjective olfactory assessments upon SARS-Cov-2 infection is comparable to quantitative evaluation, suggesting that self-reporting could be adopted as the first line of intervention, anticipating more exhaustive procedures aimed at containing COVID-19 diffusion and consequently preserving general health. Overall, results from this work share similarity with other studies, therefore further underlying that olfactory and gustatory disbalance can be distinctive hallmarks in COVID-19 continuum. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study was funded by intramural fund of the Cantonal Hospital of FR and the EKSAS fellowship from the Swiss Confederation. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: On April 27th 2020, the Ethics Cantonal Commission of Vaud (CERVD) gave ethical approval for this work under the ID license: 2020-00695 I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors