Smell and taste dysfunction in COVID-19 is associated with younger age in ambulatory settings: a multicenter cross-sectional study

TLDR: Investigation of the frequency and severity of STD in COVID-19 patients and the association with demographic characteristics, hospital admission, symptoms, comorbidities, and blood biomarkers found an older age, being hospitalized and an increased level of C-reactive protein were factors associated with a better sense of smell and/or taste.

Abstract: Background and objective Since the initial anecdotal reports of coronavirus disease 2019 (COVID-19) from China, a growing number of studies have reported on smell and/or taste dysfunction (STD) Objective: The aim of our study was to investigate the frequency and severity of STD in COVID-19 patients and to evaluate the association with demographic characteristics, hospital admission, symptoms, comorbidities, and blood biomarkers Methods We performed a multicenter cross-sectional study on patients who were positive for SARS-CoV-2 (n=846) and controls (n=143) from 15 Spanish hospitals Data on STD were collected prospectively using an in-person survey The severity of STD was categorized using a visual analog scale We analyzed time to onset, recovery rate, time to recovery, hospital admission, pneumonia, comorbidities, smoking, and symptoms Results STD was at least 2-fold more common in COVID-19-positive patients than in controls COVID-19-positive hospitalized patients were older, with a lower frequency of STD, and recovered earlier than outpatients Analysis stratified by severity of STD showed that more than half of COVID-19 patients presented severe loss of smell (537%) or taste (522%); both senses were impaired in >90% In the multivariate analysis, older age (>60 years), being hospitalized, and increased C-reactive protein were associated with a better sense of smell and/or taste COVID-19-positive patients reported improvement in smell (456%) and taste (461%) at the time of the survey; in 906% this was within 2 weeks of infection Conclusion STD is a common symptom in COVID-19 and presents mainly in young and nonhospitalized patients More studies are needed to evaluate follow-up of chemosensory impairment