Taste is an important sense that is associated with appetite and food intake. Although many studies have been reported on taste detection tests in patients with taste disorders, few studies have been conducted in healthy subjects.

　The Iwaki Health Promotion Project is a large-scale epidemiological survey of local residents. In the present study, participants in Project 2019 were tested for sweet, salty, sour, and bitter taste thresholds, and 1027 participants for whom data were available were included in the analysis.

　A comparison of the taste thresholds among the age groups showed that the sour and salty tastes thresholds increased significantly with age, and the thresholds for all tastes was significantly lower in women than in men. In addition, decreased serum zinc levels were not necessarily associated with decreased taste, but decreased serum zinc levels and decreased taste were more frequently observed in the elderly. There were quite a few patients who were not aware of any taste disorder, even though they had a decreased sense of taste on examination. This indicates that there are potential patients with taste disorders.

　Primary ciliary dyskinesia (PCD) is a genetic disorder caused by variations in the genes related to ciliary motility. Patients with PCD exhibit various clinical manifestations, such as chronic rhinosinusitis, bronchiectasis, situs inversus, infertility and otitis media with effusion. Chronic rhinosinusitis caused by PCD can be intractable. We encountered a case of suspected PCD causing intractable chronic rhinosinusitis, in whom the disease-causing gene, DNAH8, was confirmed by genetic analysis. DNAH8 is a very rare cause of PCD, and this is the first reported case in Japan.

　We reported three cases of COVID-19 who had to be hospitalized due to severe sore throat and poor oral intake. The diagnosis of COVID-19 was confirmed by a positive RT-PCR test in two patients and by a positive antigen test in one patient. All of the patients were inadequately vaccinated against COVID-19. All had COVID-19-associated acute laryngitis. None of the patients had pneumonia, and physical examination revealed general redness in the hypopharynx and larynx in all the cases. Two patients had swelling of the arytenoid region and epiglottis. None of the patients presented with loss of smell or taste. All the patients recovered from COVID-19 without sequelae. It has been reported that the Omicron variant predominantly affects the upper airways and causes acute laryngitis without olfactory dysfunction. Therefore, during the COVID-19 epidemic, it is necessary to suspect COVID-19 infection in cases of acute laryngitis and epiglottis inflammation. In addition, the clinical manifestations are similar to the symptoms of epiglottitis, and a rapid confirmation of the larynx is necessary to rule out inflammatory edema and narrowing in the upper airways.