Self-reported Smell and Taste Disorders in Patients With COVID-19: A Japanese Single-center Study

Background/Aim: Smell and taste disorders are among the most common symptoms of COVID-19. However, the relationship between smell and taste disorders and systemic symptoms is not fully understood in Japan. Patients and Methods: Questionnaires were mailed to 105 of 111 COVID-19 patients who were hospitalized at our hospital between March and July 2020 in Japan. Results: A total of 74 patients (response rate: 70.5%) completed the survey. Of these, six patients (8.1%) presented with smell disorders only, 16 (21.6%) presented with taste disorders only, and 17 (23.0%) presented with both smell and taste disorders. The mean Visual Analog Scale for smell and taste was 0.5 and 20, respectively, at the time of the most severe symptoms. Conclusion: Among COVID-19 patients in Japan, smell and taste disorders are often followed by fever and may not be the first symptoms. Sense of smell is particularly impaired. These symptoms often improve, although they sometimes persist for a long time as sequelae.