Department of Otorhinolaryngology, Kanazawa Medical University, Ishikawa, Japan.
Department of Otorhinolaryngology, Jikei University School of Medicine, Tokyo, Japan.
Rhinology. 2023 Dec 1;61(6):552-560. doi: 10.4193/Rhin23.034.
Olfactory dysfunctions (OD) and taste dysfunctions (TD) are widely recognized as characteristic symptoms of COVID-19; however, the frequency and mode of occurrence has varied depending on the viral mutation. The prevalence and characteristics of OD/TD in Japan have not been definitively investigated. The purpose of this study is to assess the prevalence of OD/TD in Japan during the Alpha variant epidemic, and measure symptom prolongation at 6 months and 1 year later following initial infection.
Patients treated for COVID-19 between February to May 2021 were evaluated for OD/TD symptoms and provided with a QOL questionnaire. Olfactory tests and taste tests were performed using Open Essence and Taste Strips, respectively.
Among the 251 COVID-19 patients who participated, 119 underwent both olfactory and taste tests. Prevalence of subjective OD and TD at the time of survey was 57.8% and 40.2%, respectively. After 12 months, the prevalence fell to 5.8% for OD and 3.5% for TD. Among the OD/TD patients, 36.6% experienced parosmia, and 55.4% experienced parageusia. Prevalence of parosmia and parageusia was higher at 6 and 12 months than at the time of survey. Patients with long-lasting disease reported qualitative dysfunctions and scored significantly higher in food-related QOL problems. Most patients who were aware of their hyposmia had low scores on the olfactory test (83.1%). In contrast, only 26.7% of patients who were aware of their hypogeusia had low scores on the taste test.
The prevalence of COVID-19-related OD and TD at the time of survey was 57.8% and 40.2%, respectively. Subjective symptoms of OD and TD persisted for one year in 5.8% and 3.5% of patients, respectively. More than half of the patients with OD or TD complained of qualitative dysfunction and a decrease in their QOL related to eating and drinking. Most patients with TD did not have true TD, but rather developed flavour disorders associated with OD. This conclusion is supported by the finding that patients with subjective OD had low scores on the olfactory test, whereas most patients with subjective TD had normal scores on the taste test.
嗅觉功能障碍（OD）和味觉功能障碍（TD）被广泛认为是 COVID-19 的特征性症状；然而，其发生的频率和方式因病毒突变而异。日本尚未明确调查 OD/TD 的流行率。本研究旨在评估 Alpha 变异株流行期间日本 OD/TD 的流行率，并测量感染后 6 个月和 1 年时的症状持续时间。
评估 2021 年 2 月至 5 月期间因 COVID-19 接受治疗的患者的 OD/TD 症状，并提供生活质量问卷。使用 Open Essence 和 Taste Strips 分别进行嗅觉测试和味觉测试。
在 251 名参与的 COVID-19 患者中，119 名患者同时进行了嗅觉和味觉测试。调查时主观 OD 和 TD 的患病率分别为 57.8%和 40.2%。12 个月后，OD 的患病率降至 5.8%，TD 的患病率降至 3.5%。在 OD/TD 患者中，36.6%出现嗅觉异常，55.4%出现味觉异常。6 个月和 12 个月时，嗅觉异常和味觉异常的患病率高于调查时。报告疾病持续时间较长的患者存在定性功能障碍，且在与饮食相关的生活质量问题上得分较高。大多数嗅觉减退的患者嗅觉测试得分较低（83.1%）。相比之下，只有 26.7%自觉味觉减退的患者味觉测试得分较低。
调查时 COVID-19 相关 OD 和 TD 的患病率分别为 57.8%和 40.2%。5.8%和 3.5%的患者分别持续 1 年存在 OD 和 TD 主观症状。超过一半的 OD 或 TD 患者抱怨定性功能障碍和与饮食相关的生活质量下降。大多数 TD 患者并非真正的 TD，而是与 OD 相关的味觉障碍。这一结论得到了以下发现的支持：即有主观 OD 的患者嗅觉测试得分较低，而大多数有主观 TD 的患者味觉测试得分正常。
