Objective olfactory evaluation of self‐reported loss of smell in a case series of 86 COVID‐19 patients

Objective To investigate olfactory dysfunction (OD) in patients with mild coronavirus disease 2019 (COVID‐19) through patient‐reported outcome questionnaires and objective psychophysical testing. Methods COVID‐19 patients with self‐reported sudden‐onset OD were recruited. Epidemiological and clinical data were collected. Nasal complaints were evaluated with the sinonasal outcome‐22. Subjective olfactory and gustatory status was evaluated with the National Health and Nutrition Examination Survey. Objective OD was evaluated using psychophysical tests. Results Eighty‐six patients completed the study. The most common symptoms were fatigue (72.9%), headache (60.0%), nasal obstruction (58.6%), and postnasal drip (48.6%). Total loss of smell was self‐reported by 61.4% of patients. Objective olfactory testings identified 41 anosmic (47.7%), 12 hyposmic (14.0%), and 33 normosmic (38.3%) patients. There was no correlation between the objective test results and subjective reports of nasal obstruction or postnasal drip. Conclusion A significant proportion of COVID‐19 patients reporting OD do not have OD on objective testing.