Unlocking the Secrets: Predictive Risk Factors for Long-term Olfactory Dysfunction in COVID-19 Patients

Abstract

<b>Introduction:</b> COVID-19 is a multisystem disease that can severely impact overall health. It causes non-lethal complications that may significantly affect the quality of life, such as smell dysfunction, which has been identified as an essential and early indicator of infection. A substantial proportion suffer from prolonged or even permanent loss of smell.<b>Aim:</b> The study aims to identify key clinical and demographic risk factors that significantly predict the prognosis of such an olfactory loss in patients with COVID-19.<b>Materials and method:</b> A prospective, cross-sectional, descriptive study. Qualified patients were aged ≥ 18 years with a past COVID-19 infection confirmed by PCR. They all underwent thorough clinical assessments and nasoendoscopy to exclude other nasal pathologies. The Alcohol Threshold Test (ATT) was used to assess olfactory function and only patients with severe hyposmia and anosmia were included in the study. The Arabic version of the Kessler Psychological Distress Scale (K10) was used to assess the emotional impact on the patient.<b>Results:</b> The study included 100 patients suffering from severe smell loss. Sixty-two patients (62%) were ≥39 years and 38 (38%) were ≤ 40 years old. The mean age of the patients was 37.5 10.8 years. There were 62 females (62%). The mean duration of olfactory loss was 4.4 2.8 months. Sudden onset was reported in 98 patients. Only 2 patients (2%) had rhinorrhea. Eighty-one patients (81%) suffered from mild symptoms of COVID infection. There were 21 smokers (21%). Eighteen patients (18%) had comorbidities. Twenty-seven patients (27%) belonged to the low socioeconomic status. Severe hyposmia (TS of ATT = 4–5) was reported in 96 patients (96%) and anosmia (TS of ATT = 6) in 4 patients (4%). Kessler’s test indicated that 63 patients (63%) experienced moderate to severe distress.<b>Conclusions:</b> The following risk factors showed significant differences in the prognosis of olfactory loss: older age, long duration of loss, smoking, presence of comorbidities, low socioeconomic status, and increased severity of COVID-19. These factors may be important predictors of the persistence of olfactory loss. Factors like sex, onset type, nasal symptoms, severity of olfactory loss, and Kessler’s test score did not show significant differences.