Persistent Loss of smell associated with long COVID could be permanent: JAMA

Determining the characteristics, type, and severity of olfactory dysfunction in patients with long COVID is important for the prognosis and potential treatment of the affected population.

A study was conducted to describe the sociodemographic and clinical features of patients with long COVID who develop persistent olfactory dysfunction.

This cross-sectional study, conducted at a rehabilitation centre at a public university in the Amazon region of Brazil between September 9, 2020, and October 20, 2021, comprised 219 patients with long COVID and self-reported neurologic symptoms. Of these 219 patients, 139 received a diagnosis of chronic olfactory dysfunction, as confirmed by the Connecticut Chemosensory Clinical Research Center (CCCRC) test.

Results:

• Of the 219 patients included in the study, 164 (74.9%) were women, 194 (88.6%) were between 18 and 59 years of age, 206 (94.1%) had more than 9 years of education, and 115 (52.5%) had a monthly income of up to US $192.00.
• In the study group, 139 patients (63.5%) had some degree of olfactory dysfunction, whereas 80 patients (36.5%) had normosmia.
• Patients with olfactory dysfunction had a significantly longer duration of long COVID symptoms than those in the normosmia group
• Among patients with anosmia, there was a significant association between olfactory dysfunction and daily activities, especially in terms of impairment in hazard detection, personal hygiene
• Univariable logistic regression analyses found that ageusia symptoms were associated with the occurrence of olfactory dysfunction whereas headache and sleep disorders showed an inverse association with the occurrence of olfactory dysfunction.

Olfactory dysfunction is one of the most important long-term neurologic symptoms of COVID-19, with the highest prevalence seen among women, adults, and outpatients. Patients with olfactory dysfunction may experience persistent severe hyposmia or anosmia more than 1 year from the onset of symptoms, suggesting the possibility of the condition becoming a permanent sequela.

Reference:

Mendes Paranhos AC, Nazareth Dias ÁR, Machado da Silva LC, et al. Sociodemographic Characteristics and Comorbidities of Patients With Long COVID and Persistent Olfactory Dysfunction. JAMA Netw Open. 2022;5(9):e2230637. doi:10.1001/jamanetworkopen.2022.30637

Keywords:

Sociodemographic, Characteristics, Comorbidities, Patients, Long, COVID, Persistent, Olfactory Dysfunction, Alna Carolina Mendes Paranhos, Nazareth Dias ÁR, Machado da Silva LC, JAMA Netw Open