Loss of Smell in COVID-19 Patients: New Biomarkers

Patients with emerging anosmia may be asymptomatic carriers of coronavirus disease 2019 infection requiring self-isolation; otherwise, there are risks of facilitating the spread of the disease.This study aims to evaluate the loss of smell with visual analogue scale and to determine the relationship between the loss of smell and blood parameters.All patients' coronavirus disease 2019 swab cultures were polymerase chain reaction positive and pneumonia was found in computed tomographies consistent with oronavirus disease 2019. The study was conducted on 114 patients hospitalized between 01.11.2020 and 31.12.2020 in the Otorhinolaryngology coronavirus disease 2019 Service of University of Health Sciences Adana City Training and Research Hospital and followed up by us.A score of 10 indicates that the olfactory function is completely normal in all patients undergoing visual analogue scale, and a score of 0 indicates that they cannot smell anything. Patients who received visual analogue scale scored 10 points were categorized as Group 1 and others as Group 2. Statistical significance level was determined as p < 0.05. A statistically significant difference was found between Group 1 and Group 2 in terms of visual analogue scale smell score, neutrophil, lymphocyte, neutrophil–lymphocyte ratio. Visual analogue scale smell score, neutrophil count, neutrophil–lymphocyte ratio value were found to be lower in Group 2 and lymphocyte count was found to be higher. Neutrophil, lymphocyte, neutrophil/lymphocyte ratio, platelet, platelet/lymphocyte ratio, which are also used in nasal diseases, may be used to detect loss of smell, predict, and even determine the prognosis of loss of smell if supported by further studies.