Sustained Chemosensory Dysfunction during the COVID-19 Pandemic.

Area of Science:

• Infectious Diseases
• Neurology
• Otolaryngology

Background:

• Chemosensory dysfunction (CD), including loss of smell and taste, is a frequent and specific symptom of COVID-19.
• Understanding the duration and recovery patterns of CD is crucial for managing patients post-SARS-CoV-2 infection.

Purpose of the Study:

• To investigate the duration of chemosensory dysfunction in patients experiencing sudden olfactory and/or gustatory loss during the COVID-19 pandemic.
• To identify prognostic factors influencing the duration of CD.

Main Methods:

• An online questionnaire assessed subjective CD at baseline.
• Follow-up questionnaires were administered every 6 weeks to participants with persistent CD.
• Prospective assessment of chemosensory function over an extended follow-up period.

Main Results:

• Significant improvement in chemosensory function occurred within the first month, with recovery rates plateauing around 2 months.
• After a mean follow-up of ~95 days, 82.6% reported olfactory improvement and 86.7% reported gustatory improvement.
• Full recovery was reported by 43.8% for olfaction and 55.0% for gustation; female gender correlated with better gustatory improvement, while high symptom severity correlated with poorer olfactory and gustatory recovery.

Conclusions:

• Chemosensory dysfunction improvement and recovery rates decline after 2-4 months, suggesting potential for prolonged or permanent loss post-COVID-19.
• Higher subjective severity of chemosensory loss is associated with a worse prognosis for recovery.