Objective gustatory and olfactory dysfunction in COVID-19 patients: a prospective cross-sectional study

PURPOSE: To determine the prevalence of objective gustatory (GD) and olfactory (OD) dysfunction in COVID-19 patients. METHODS: This is a prospective, cross-sectional study of 51 COVID-19 positive patients diagnosed using RT-PCR-based testing. Of these study participants, 41 reported having present GD and OD at the time of enrollment and ten patients were without symptomatic OD and GD. All participants were objectively tested for OD by Brief Smell Identification Test (BSIT) and for GD by Burghart taste strip test, which were mailed to the participants. The subjective presence and severity of COVID-19 symptoms of smell loss, loss of taste, nasal obstruction, rhinorrhea/mucus production, fever, cough and shortness of breath were also assessed. RESULTS: Of the 41 patients with GD and OD, only 25.6% (10/39; p ≤ 0.0001) objectively presented GD and 39.1% (16/41; p ≤ 0.0001) OD at the time of their subjective dysfunction. Regarding GD, 23.1% (9/39) suffered from total hypogeusia, 2.6% (1/39) from ageusia. A significant loss of sour (33.3% (13/39)) and salty taste (17.9% (7/39)) could be recognized. Only 10.3% (4/39) showed a reduction in sweet and bitter taste. Concerning OD, 9.8% (4/41) showed a deficit relative to younger age in the BSIT and 29.3% (12/41) results abnormal relative to age. CONCLUSION: Subjective and objective findings in GD and OD differ significantly. Most patients suffering from objective dysgeusia present a deficit in sour and salty taste. TRIAL REGISTRATION NUMBER: DRKS00021516; 22/04/2020.