Most COVID-Related Smell, Taste Dysfunction Resolved at 2 Years

Most patients with smell or taste dysfunction related to COVID-19 reported complete recovery of their senses at 2 years, according to a cross-sectional survey conducted in Italy.

Among 119 patients with smell or taste dysfunction within 4 weeks of COVID onset, 88.2% reported complete resolution at 2 years, 9.2% reported a decline in symptom severity, and 2.5% reported unchanged or worsening symptoms, said Paolo Boscolo-Rizzo, MD, of the University of Trieste, and colleagues.

Late recovery (>6 months after onset) was reported by 10.9% of patients, they noted in a research letter published in JAMA Otolaryngology–Head & Neck Surgery.

“Moreover, smell and/or taste dysfunction are prevalent symptoms of long-term COVID-19, with 7% of patients being functionally anosmic 1 year after SARS-CoV-2 infection,” Boscolo-Rizzo and team wrote. “Given the high case rate of COVID-19, it is important to estimate the long-term persistence of these symptoms.”

Other symptoms associated with long COVID-19 were also reported at the 2-year follow-up, with 18.5% of patients reporting fatigue and 10.7% reporting shortness of breath.

A total of 47 patients (28.0%) were still experiencing at least one symptom at 2 years.

Boscolo-Rizzo and colleagues had previously described the prevalence of smell or taste dysfunction in mildly symptomatic patients at onset, and at 4 weeks, 8 weeks, and 6 months after infection.

“Contrary to what is often reported, patients should be reassured that recovery from smell or taste impairment may continue for many months after the onset,” the authors noted. “These results apply to patients infected in the pre-Omicron period. COVID-19 driven by the SARS-CoV-2 Omicron variant has been indeed observed to less frequently and less severely affect chemosensory function.”

For the current study, data were taken from adults who tested positive for COVID-19 via PCR at Treviso General Hospital from March 19-22, 2020. All patients included were able to return home to recover, and were contacted for follow-up at 4 weeks, 8 weeks, 6 months, and 2 years, with the same questions being administered.

Patients with documented COVID reinfections and those with late onset (>3 months) of altered smell or taste that suggested possible reinfection were excluded.

Of 168 eligible patients, median age was 55 years, and 53.6% were women. Among them, 108 reported smell or taste dysfunction (Sino-nasal Outcome Test 22 score >0) at baseline, 64 at 4 weeks, 29 at 8 weeks, 27 at 6 months, and 14 at 2 years.

Boscolo-Rizzo and colleagues noted that the data were self-reported and were taken from a small sample size, and patients with more severe symptoms were excluded. There was also no available information on possible treatments for sensory impairments, and outcomes not specifically validated for olfactory loss were not included.