Severity of Anosmia as an Early Symptom of COVID-19 Infection May Predict Lasting Loss of Smell
Jérôme R. Lechien, Fabrice Journé, Stéphane Hans, Carlos M. Chiesa‐Estomba, Vincent Mustin, Eline Beckers, Luigi Angelo Vaira, Giacomo De Riu, Claire Hopkins, Sven Saussez
Abstract
Introduction: To evaluate the recovery rate of loss of smell (LOS) with objective olfactory testing in COVID-19 patients. Methods: Adults with confirmed COVID-19 and self-reported sudden LOS were prospectively recruited through a public call from the University of Mons (Belgium). Epidemiological and clinical data were collected using online patient-reported outcome questionnaires. Patients benefited from objective olfactory evaluation (Sniffin-Sticks-test) and were invited to attend for repeated evaluation until scores returned to normal levels. Results: From March 22 to May 22, 2020, 88 patients with sudden-onset LOS completed the evaluations. LOS developed after general symptoms in 44.6% of cases. Regarding objective evaluation, 22 patients (25.0%) recovered olfaction within 14 days following the onset of LOS. The smell function recovered between the 16th and the 70th day post-LOS in 48 patients (54.5%). At the time of final assessment at 2 months, 20.5% of patients ( N = 18) had not achieved normal levels of olfactory function. Higher baseline severity of olfactory loss measured using Sniffin-Sticks was strongly predictive of persistent loss ( p < 0.001). Conclusion: In the first 2 months, 79.5% of patients may expect to have complete recovery of their olfactory function. The severity of olfactory loss, as detected at the first Sniffin-Sticks-test, may predict the lack of mid-term recovery.