Recovery from COVID-19-related olfactory disorders and quality of life: insights from an observational online study.

Ferdenzi, Camille; Bousquet, Christophe; Aguera, Pierre-Emmanuel; Dantec, Morgane; Daudé, Christelle; Fornoni, Lesly; Fournel, Arnaud; Kassan, Aurélien; Mantel, Marylou; Moranges, Maëlle; Moussy, Erwan; Richard Ortegón, Stéphane; Rouby, Catherine; Bensafi, Moustafa

Although olfactory disorders (OD) are among the most significant symptoms of COVID-19, recovery time from COVID-19 related OD as well as their consequences on the quality of life remain poorly documented. We investigated the characteristics and behavioral consequences of COVID-19 related OD using a large-scale study involving 3111 French respondents (78% women) to an online questionnaire over a period of 9 months covering different epidemic waves (from April 8 th 2020 to January 13 th 2021). In the patients who subjectively recovered from COVID-19 related OD (N = 609), recovery occurred on average after 16 days and most of the time within one month ("normal" recovery range); 49 subjectively recovered in 1 to 2.5 months, and several cases took up to 6.5 months. Among the patients with ongoing OD (N = 2502), 974 were outside the "normal" recovery range (persistent OD) and reported OD for 1 to 10 months. Developing a persistent OD was more likely with increasing age and in women, and was more often associated with parosmia and phantosmia. The deleterious impact of COVID-19 related OD on the quality of life was significantly aggravated by OD duration, and was more pronounced in women. Because persistent OD is not infrequent after COVID-19, has deleterious consequences on the quality of life, and receives few solutions from the health practitioners, it would be beneficial to implement screening and treatment programs to minimize the long-term behavioral consequences of COVID-19 related OD.