Sudden anosmia without rhinitis is suggestive of early COVID-19

  • Haehner A, & et al
  • medRxiv
  • 4 May 2020

  • curated by Liz Scherer
  • Clinical Essentials
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Takeaway

  • Acute anosmia appears to be an early symptom of COVID-19 disease and commonly occurs independently of rhinitis, according to findings of a German cohort study that has not yet undergone peer-review.

Why this matters

  • Consider coronavirus testing in patients presenting with unusual, sudden loss of smell and taste without severe nasal blockage, especially patients age 

Key results

  • 500 patients; mean age, 41.3 (range, 18-86) years.
  • 466 tested RT-PCR negative for SARS-CoV-2; 34 tested positive.
  • 64.7% (22/34) of patients who tested positive complained of sudden olfactory impairment.
  • Timing of the loss relative to other symptoms:
    • 1-2 days before other symptoms: n=1.
    • Simultaneously: n=4. 
    • 1-7 days after: n=14; 
    • Unsure: n=3.
  • Patients with anosmia were younger (P=.04) vs patients without it.
  • Smell visual analogue scale: −6.8±2.3 (median±standard deviation), nasal breathing, −1.1±1.6.
  • 45.5% vs 80.9% (SARS-CoV-2 positive vs negative) complained of rhinorrhea.
  • Nasal airflow changes were more pronounced in patients with smell loss complaints testing negative vs positive (P<.001>
  • Olfactory function changes were more severe in patients testing SARS-CoV-2 positive (P=.023).
  • Smell loss as sole symptom: 65% sensitivity, 90% specificity, 32% positive predictive value, 97% negative predictive value.

Study design

  • Cross-sectional controlled cohort analysis of olfactory loss frequency, diagnostic value of symptom, among outpatients in Germany presenting for coronavirus testing during a 2-week period.
  • Funding: None.

Limitations

  • Preprint.
  • Self-report/recall bias.
  • Temporal relationship unclear.