- Olfactory dysfunction in patients with mild-to-moderate COVID-19 might be more widespread than previously believed and occurring in multiple clinical forms.
- Studies are needed to assess pathological mechanisms, viral spread through olfactory neuroepithelium, invasion of olfactory bulb, and central nervous system.
Why this matters
- Clinicians should be alert to loss of smell and taste as symptoms of mild-to-moderate COVID-19.
- 2013 participants; 8% (161) were hospitalized for COVID-19.
- 87.2% reported loss of smell.
- 56.4% reported taste dysfunction.
- Mean time from end of disease to evaluation: 7.8 (standard deviation [SD], 6.8) days.
- Mean duration of nonolfactory symptoms: 11.5 (SD, 6.0) days.
- 65.4% who had olfactory dysfunction did so after other general or otolaryngologic symptoms.
- 573 patients regained sense of smell:
- 60.9% of this group regained sense of smell at 5-14 days after loss (mean duration, 8.4 [SD, 5.1] days).
- Of 86 patients completing an objective olfactory evaluation:
- 47.7% had confirmed anosmia.
- 14.0% had confirmed hyposmia.
- 38.3% had no signs of dysfunction.
- No significant association was identified between loss of smell and nasal obstruction, rhinorrhea, or postnasal drip.
- Cross-sectional evaluation of prevalence, features, recovery from smell dysfunction in hospitalized and ambulatory patients recovering from mild-to-moderate COVID-19 in Europe, March 22, 2020 to April 23, 2020.
- Funding: None disclosed.
- Self-report bias.
- Generalizability unknown.