Acute‐onset smell and taste disorders in the context of COVID‐19: a pilot multicentre polymerase chain reaction based case–control study

Abstract

Background Specific respiratory tract infections, including Covid‐19, may cause smell and/or taste disorders (STD) with increased frequency. We aim to determine whether new‐onset STD are more frequent among Covid‐19 patients than influenza patients. Methods Case‐control study including hospitalized patients of two tertiary care centers. Consecutive patients positive for Covid‐19 PCR (cases) and patients positive for influenza PCR (historical control sample) were assessed during specific periods, employing a self‐reported STD questionnaire. Results Seventy‐nine cases and 40 controls were included. No significant differences were found in basal features between both groups. New‐onset STD were significantly more frequent among cases (31, 39.2%) than in the control group (5, 12.5 %), adjusted OR 21.4 (2.77‐165.4, p=0.003). Covid‐19 patients with new‐onset STD were significantly younger than Covid‐19 patients without STD (52.6 ± 17.2 vs. 67.4 ±15.1, p<0,001). Among Covid‐19 patients who presented STD, 22 (70.9%) recalled an acute onset and was an initial manifestation in 11 (35.5%). Twenty‐five (80.6%) presented smell disorders (mostly anosmia, 14, 45.2%), and 28 (90.3%) taste disorders (mostly ageusia, 14, 45.2%). Only four (12.9 %) reported concomitant nasal obstruction. Mean duration of STD was 7.5 ± 3.2 days and 12 patients (40%) manifested complete recovery after 7.4 ± 2.3 days of onset. Conclusion New‐onset STD were significantly more frequent among Covid‐19 patients than influenza patients, they usually had an acute onset and were commonly an initial manifestation. We suggest the use of STD assessment in anamnesis as a hint for Covid‐19 and to support individuals’ self‐isolation in the current epidemic context.