To analyse the correlations between olfactory psychophysical scores and the serum levels of D-dimer, C-reactive protein, ferritin, lactate dehydrogenase, procalcitonin and neutrophil-to-lymphocyte ratio in coronavirus disease 2019 patients.

Patients underwent psychophysical olfactory assessment with the Connecticut Chemosensory Clinical Research Center test, and determination of blood serum levels of the inflammatory markers D-dimer, C-reactive protein, ferritin, lactate dehydrogenase, procalcitonin and neutrophil-to-lymphocyte ratio within 10 days of the clinical onset of coronavirus disease 2019 and 60 days after.

Seventy-seven patients were included in this study. D-dimer, procalcitonin, ferritin and neutrophil-to-lymphocyte ratio correlated significantly with severe coronavirus disease 2019. No significant correlations were found between baseline and 60-day Connecticut Chemosensory Clinical Research Center test scores and the inflammatory markers assessed.

Olfactory disturbances appear to have little prognostic value in predicting the severity of coronavirus disease 2019 compared to D-dimer, ferritin, procalcitonin and neutrophil-to-lymphocyte ratio. The lack of correlation between the severity and duration of olfactory disturbances and serum levels of inflammatory markers seems to further suggest that the pathogenetic mechanisms underlying the loss of smell in coronavirus disease 2019 patients are related to local rather than systemic inflammatory factors.