Mangal Vishal, Murari T, Vashisht Rohit, Iqbal Shaik Mohammad, Meghana Kodavati, Gujrathi Sagar, Ambade Vivek, Tilak Tvsvgk, Aggarwal Vivek, Manrai Manish, Verma Vishesh, Srinath Rajagopal, Goel Nidhi, Yadav Navin Kumar, Menon Anil
Department of Internal Medicine, Armed Forces Medical College, Pune, Maharashtra 411040 India.
Department of Otorhinolaryngology & Head and Neck Surgery, Armed Forces Medical College, Pune, Maharashtra 411040 India.
Indian J Otolaryngol Head Neck Surg. 2021 Jun;73(2):212-217. doi: 10.1007/s12070-021-02366-6. Epub 2021 Feb 10.
Olfactory dysfunction (hyposmia, anosmia) is a well-recognized symptom in patients with coronavirus disease-19 (COVID-19). Studies of olfactory dysfunction in asymptomatic patients have not been reported. We conducted a study looking for the presence of olfactory dysfunction with an objective assessment tool in asymptomatic Covid 19 and compared it with patients with mild COVID-19 and age-matched controls. We recruited 57 male patients each of Mild COVID-19, asymptomatic Covid 19, and healthy controls for the study. All participants underwent evaluation of smell threshold by Butanol Threshold test (BTT) and ability to distinguish common odors by Smell identification test. The scores of each test were recorded on a numerical scale. The participants in all three arms were matched for age, history of smoking, and pre-existing medical conditions. The mean scores of the Butanol Threshold test in Mild COVID-19, asymptomatic Covid 19 and controls were 2.95 ± 2.25 (0-7.5), 3.42 ± 2.23 (0-7.5), and 4.82 ± 1.86 (0-8), respectively. A one-way ANOVA showed a significant difference between groups (df 2, MS 53.78, F 11.94, < 0.005). Intergroup differences using the student T-test showed significantly low BTT scores in Mild COVID-19 ( < 0.005) and asymptomatic ( < 0.005) as compared to control. BTT scores could not distinguish between asymptomatic patients and control. The smell threshold was impaired in asymptomatic Covid 19 and Mild COVID-19. Butanol Threshold Test score could not differentiate between asymptomatic Covid 19 and controls.
嗅觉功能障碍（嗅觉减退、嗅觉丧失）是冠状病毒病19（COVID-19）患者中一种广为人知的症状。关于无症状患者嗅觉功能障碍的研究尚未见报道。我们进行了一项研究，使用客观评估工具寻找无症状COVID-19患者中嗅觉功能障碍的存在情况，并将其与轻度COVID-19患者及年龄匹配的对照组进行比较。我们招募了57名男性患者，分别为轻度COVID-19患者、无症状COVID-19患者和健康对照组，进行此项研究。所有参与者均通过丁醇阈值测试（BTT）评估嗅觉阈值，并通过嗅觉识别测试评估辨别常见气味的能力。每项测试的分数都以数字量表记录。三组参与者在年龄、吸烟史和既往病史方面进行了匹配。轻度COVID-19组、无症状COVID-19组和对照组的丁醇阈值测试平均分数分别为2.95±2.25（0 - 7.5）、3.42±2.23（0 - 7.5）和4.82±1.86（0 - 8）。单因素方差分析显示组间存在显著差异（自由度2，均方53.78，F值11.94，P<0.005）。使用学生t检验的组间差异显示，与对照组相比，轻度COVID-19组（P<0.005）和无症状组（P<0.005）的BTT分数显著较低。BTT分数无法区分无症状患者和对照组。无症状COVID-19和轻度COVID-19患者的嗅觉阈值均受损。丁醇阈值测试分数无法区分无症状COVID-19患者和对照组。
