Loss of smell from COVID most likely means you’ve got a mild case, study finds

(StudyFinds.org) — Losing your sense of smell might indicate that you have a mild case of COVID-19, according to a study published earlier this year. Statistics show that patients suffering moderate and severe cases of the infection are far less likely to experience the symptom.

In a study of 2,581 patients from 18 European hospitals, patients suffered a loss of smell in 85.9 percent of mild cases of COVID-19. That’s compared to 4.5 percent in moderate Covid-19 cases and nearly 7 percent in severe-to-critical cases. While those figures were patient-reported, objective clinical evaluations found a loss of smell in 54.7 percent of mild COVID cases and 36.6 percent of moderate-to-critical cases.

Mild cases were defined as patients without evidence of viral pneumonia or hypoxia – a lack of oxygen – who usually recovered at home, while severe cases involved being taken to hospital.

The study examined the prevalence and recovery in patients with varying degrees of severity of the virus. “Olfactory dysfunction is more prevalent in mild COVID-19 forms than in moderate-to-critical forms, and 95 percent of patients recover their sense of smell at six months post-infection,” says professor Jerome Lechien, a lead author of the study at Paris-Saclay University in France, in a statement.

The average time of olfactory dysfunction reported by patients was 21.6 days. After two months, almost a quarter (24.1%) of patients still suffered from a lack of smell, also known as anosmia. That number dropped to 15.3% of patients at 60 days post-infection, and nearly 5% at the six-month mark.

Young patients could have a higher rate of anosmia compared with elderly people.

“At the two months of follow-up, 75 percent to 85 percent of patients recovered olfaction according to subjective and objective olfactory evaluations. The main hypothesis underlying the higher prevalence of anosmia in mild COVID-19 would consist of differences in the immune response to the infection in mild and moderate-to-critical patients. Future studies are needed to determine the long-term recovery rate of COVID-19 patients,” the authors write.