The relationship between intravenous olfactory test and taste disorder in patients with olfactory disorder

Background: The intravenous olfactory test (alinamin test [AT]) is a retronasal olfactory assessment and may evaluate the flavour disorder; however, studies assessing whether AT accurately determines the severity of taste disorders are lacking. Our study aims to evaluate the relationship between AT and subjective taste disorders in the patiensts with olfactory disorder. Methods: Between April 2019 and March 2020, 228 patients visited our smell clinic reporting olfactory disorders. Of these, 193 patients who underwent AT were included in this study. We evaluated the differences in AT response, latency time, and duration time between patients with and without subjective taste disorder. We also assessed the degree of subjective taste disorder experienced by patients using the visual analogue scale (VAS) and the correlation between latency and duration time of AT. To assess taste perception more broadly, we inquired about the presence of disorder using the term "taste" rather than "flavour,"without focusing on any specific type of taste disorder. Results: Of the included 193 patients, 62 reported awareness of a taste disorder. The duration time of AT was significantly shorter in patients with subjective taste disorder. A weak correlation was found between the VAS scores for subjective taste disorders and the duration time of AT. Conclusions: Our results showed that among the patients with olfactory disorders, the duration time of AT was reduced for those with subjective taste disorders.