Olfactory Dysfunction is Associated with More Severe Clinical Course in COVID-19

Abstract

To perform a quantitative olfactory test in positive COVID19 RT-PCR admitted patients and asymptomatic ones, to evaluate the association between hyposmia and disease severity. This is a Cross sectional study. Ninety-one patients including 68 inpatients and 23 asymptomatic healthcare workers with positive COVID-19 RT-PCRs. Methods: Demographics and clinical characteristics were collected. Iran Smell Identification Test (IR-SIT), a highly accurate 6-odorant test was used to evaluate the reliability of self-reported hyposmia and determine the correlation of the measured olfactory dysfunction with disease severity. Twenty-two of 91 patients (24%) reported hyposmia, while 41/91 (45%) patients had measurable olfactory dysfunction (IR-SIT score 1–4, p < 0.05). Mean age of the 68 inpatients and 23 asymptomatic patients were 43.97 ± 16.13 years; M:F 43:25, and 43.87 ± 12.76 years; M:F 8:15 respectively. Of 68 patients, 20 were graded as severe, and 48/68 had mild course of disease. IR-SIT detected hyposmia in 80% of patients with severe disease, and 50% with mild disease, respectively. The risk of disease severity was significantly increased for patients with olfactory dysfunction and was detected 4 times higher when compared to patients with mild disease (OR 4, 95% CI: 1.166–13.728, p = 0.028). Olfactory Dysfunction was present in 80% of patients with severe course. The risk of disease severity is significantly increased with olfactory dysfunction in admitted patients.

Patients with COVID-19-associated olfactory impairment also show impaired trigeminal function

“…Histological samples from the nose and immunohistochemical staining of the trigeminal nerve branches in SARS-CoV-2 infected persons may provide more detailed information. Of note, there is increasing evidence that patients with an affection of the nasal senses could have a more severe course of the disease [27] or more neurological symptoms [28].…”

The role of smoking in COVID-19 progression: a comprehensive meta-analysis

“…length of stay, intensity of medical care, complicated versus noncomplicated). Five studies [16][17][18][19][20] reported data on the association between smoking and symptomatic versus asymptomatic SARS-CoV-2-positive individuals. These studies were included in the meta-analysis of hospitalisation because the study population was the same (i.e.…”

Olfactory Dysfunction in Patients With Coronavirus Disease 2019: A Review

“…In contrast, Singer-Cornelius et al suggested, based on a lack of significant associations between the two conditions in objective tests, that GD and OD are two independent symptoms ( 37 ). A negative correlation has been demonstrated between OD and post-admission severity and mortality of COVID-19 in several studies ( 49 , 50 ), in direct contrast to a report on clinical outcomes by Tabari et al ( 51 ). Speth et al showed that in addition to GD, OD severity was significantly associated with depression and anxiety ( 52 ).…”