Severity of Anosmia as an Early Symptom of COVID-19 Infection May Predict Lasting Loss of Smell

• Published in: Frontiers in medicine 2020-11, Vol.7, p.582802-582802
• Main Authors: Lechien, Jerome R, Journe, Fabrice, Hans, Stephane, Chiesa-Estomba, Carlos M, Mustin, Vincent, Beckers, Eline, Vaira, Luigi A, De Riu, Giacomo, Hopkins, Claire, Saussez, Sven
• Format: Article
• Language: English
• Subjects: anosmia; COVID-19; Medicine; neuroepithelia; objective test; recovery
• ISSN: 2296-858X; 2296-858X
• DOI: 10.3389/fmed.2020.582802

To evaluate the recovery rate of loss of smell (LOS) with objective olfactory testing in COVID-19 patients. 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. 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 ( = 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 ( < 0.001). 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.