Parosmia Is Distinct from Quantitative Olfactory Loss in Patients with COVID-19–Related Dysfunction

by Linda Kossoff •

What are the clinical features, risk factors, symptom time-course, and quality-of-life implications for parosmia among COVID-related olfactory dysfunction patients?

BOTTOM LINE

Parosmia is a form of qualitative olfactory dysfunction that is distinct from quantitative olfactory loss and persists after COVID-19 infection in a substantial number of patients.

BACKGROUND: COVID-19 is frequently associated with new-onset olfactory dysfunction. Many COVID-19 patients experience parosmia, a qualitative form of olfactory dysfunction, during their clinical course. Although the association between COVID-19 and parosmia has been widely reported, there has been inadequate characterization of parosmia as a clinical entity distinct from quantitative olfactory loss.

STUDY DESIGN: Prospective cross-sectional cohort study.

SETTING: Department of Otolaryngology, Icahn School of Medicine at Mount Sinai, New York, N.Y.

SYNOPSIS: Researchers recruited 231 adults seen at multiple otolaryngology and primary care practices and associated with laboratory-confirmed or clinically suspected COVID-19 infection and self-reported new-onset olfactory dysfunction. All subjects completed olfactory dysfunction and quality-of-life surveys. During the study time frame, 148 respondents reported parosmia symptoms, which developed within one week of any COVID-19 symptom onset in 25.4% of subjects, and more than one month after symptom onset in 43.4% subjects. Respondents who developed parosmia were significantly younger than those who did not (40.2 years vs 44.9 years) and less likely to have history of chronic sinusitis (7.2% vs 0.7%). There were no significant differences in gender, smoking history, current smoker status, or history of head trauma, allergic rhinitis, or sinonasal surgery between groups. Parosmia was associated with significantly better quantitative olfactory scores but worse quality-of-life scores. Self-reported symptom severity remained high among parosmia patients who responded to a follow-up survey at an average of 244.8 days after symptom onset. Limitations included the specific composition of motivated subjects and reliance on survey responses.

CITATION: Lerner DK, Garvey KL, Arrighi-Allisan AE, et al. Clinical features of parosmia associated with COVID-19 infection. Laryngoscope. 2022;132:633-639.