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

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,  < 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,  = 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.