The long-term effect of COVID-19 infection on olfaction and taste; a prospective analysis

Eur Arch Otorhinolaryngol. 2024 Nov;281(11):6001-6007. doi: 10.1007/s00405-024-08827-2. Epub 2024 Jul 8.

Abstract

Purpose: To estimate long-term prognosis of chemosensory dysfunctions among patients recovering from COVID-19 disease.

Methods: Between April 2020 and July 2022, we conducted a prospective, observational study enrolling 48 patients who experienced smell and/or taste dysfunction during the acute-phase of COVID-19. Patients were evaluated for chemosensory function up to 24 months after disease onset.

Results: During the acute-phase of COVID-19, 80% of patients reported anosmia, 15% hyposmia, 63% ageusia, and 33% hypogeusia. At two years' follow-up, 53% still experienced smell impairment, and 42% suffered from taste impairment. Moreover, 63% of patients who reported parosmia remained with olfactory disturbance. Interestingly, we found a negative correlation between visual analogue scale scores for smell and taste impairments during the acute-phase of COVID-19 and the likelihood of long-term recovery.

Conclusion: Our study sheds light on the natural history and long-term follow-up of chemosensory dysfunction in patients recovering from COVID-19 disease. Most patients who initially suffered from smell and/or taste disturbance did not reach full recovery after 2 years follow-up. The severity of impairment may serve as a prognostic indicator for full recovery.

Keywords: Ageusia; Anosmia; COVID-19; Chemosensory function; Parosmia; Smell.

Publication types

  • Observational Study

MeSH terms

  • Adult
  • Aged
  • COVID-19* / complications
  • COVID-19* / epidemiology
  • COVID-19* / physiopathology
  • Female
  • Humans
  • Male
  • Middle Aged
  • Olfaction Disorders* / epidemiology
  • Olfaction Disorders* / etiology
  • Olfaction Disorders* / physiopathology
  • Olfaction Disorders* / virology
  • Prognosis
  • Prospective Studies
  • SARS-CoV-2
  • Taste Disorders* / epidemiology
  • Taste Disorders* / etiology
  • Taste Disorders* / physiopathology
  • Taste Disorders* / virology