Story at a glance
- Scientists estimate that based on new results, the full return of smell after a COVID-19 infection can take up to one year.
- The loss of taste and smell are both well-documented side effects of a COVID-19 infection.
- The study featured both objective tests and self-assessments.
A new study suggests that one particular symptom of COVID-19 could take up to a year to return for some.
Published on June 24 in the JAMA medical journal, the study analyzed a small cohort of patients recovering from COVID-19 to observe if they develop anosmia — or the loss of smell — during their infection, and after.
Looking at 97 patients with acute smell loss that lasted for more than seven days following a positive COVID-19 test result, researchers monitored the entire cohort until they recovered from their losses of smell.
They found that at the four month mark, 45.1 percent of the patients reported having complete olfaction back, while another 52.9 percent reported a partial recovery.
Two percent reported no change in symptoms at that time.
More objective scientific tests were conducted to corroborate the patient’s accounts of their senses. Using these tests, a larger proportion of 84.3 percent of patients were considered normosmic — having normal olfactory sensations — including 70 percent of those who stated they were just partially recovered.
The remaining eight patients were continuously monitored.
Researchers followed up after eight months and found that 96.1 percent of the 97 patients in the cohort had fully recovered, with two patients remaining hyposmic, or living with a deteriorated sense of smell, one year after their COVID-19 infection.
The study added that there was a noted discrepancy between patient evaluations and more objective scientific tests. Scientists note both are equally valuable forms of feedback and should both be administered.
“Persistent COVID-19–related anosmia has an excellent prognosis with nearly complete recovery at 1 year,” the authors conclude. “As clinicians manage an increasing number of people with post-COVID syndrome, data on long-term outcomes are needed for informed prognostication and counseling.”