Study: Long-COVID-19 olfactory dysfunction may become permanent

Editor's Note

In this study from Brazil, researchers find that olfactory dysfunction (ie, reduced or distorted ability to smell during sniffing or eating) in patients with long COVID-19 may persist for more than 1 year and may become permanent.

Of 219 patients (164 [74.9%] women) with long COVID-19 and neurologic symptoms:

• 139 had some degree of olfactory dysfunction, whereas, 80 had normosmia (ie, normal sense of smell)
• those with olfactory dysfunction had a significantly longer duration of long COVID-19 symptoms than those with normosmia (242.7 vs 221.0 days)
• in those with anosmia (ie, loss of smell), there was a significant association between olfactory dysfunction and daily activities—ie, impairment in hazard detection, personal hygiene, and food intake.

Univariable logistic regression analyses found that ageusia (ie, loss of sense of taste) symptoms were associated with olfactory dysfunction, whereas, headache and sleep disorders showed an inverse association. Multivariate logistic regression analyses found that olfactory dysfunction was significantly associated with ageusia symptoms.

The results highlight the need to continue monitoring the rate of recovery of olfactory function in those with long COVID-19 to evaluate whether it is a chronic or permanent sequela, the researchers say.