Introduction

Hyposmia is among the most common symptoms of COVID-19 patients. Previous research has mainly described this issue at the disease’s early stages. Because olfactory impairment can indicate neurological degeneration, we investigated the possibility of permanent olfactory damage by assessing hyposmia during the late recovery stage of COVID-19 patients.

Methods

Ninety-five patients were assessed with the Brief Smell Identification Test for Chinese (B-SITC) and Hyposmia Rating Scale (HRS) after 16 weeks from disease onset. Five weeks later, 41 patients were retested with B-SITC.

Results

At the first visit, hyposmia was identified in 26/82 (31.7%) and 22/95 (23.2%) of participants by HRS (HRS score ≤22) and B-SITC (B-SITC score <8), respectively. The rates of hyposmia in patients who performed B-SITC after 14–15 weeks, 16–17 weeks, and ≥18 weeks from disease onset were 7/25 (28%), 8/35 (23%) and 7/35 (20%), respectively, which demonstrated a trend of olfaction improvement as recovery time prolonging. Hyposmia percentages decreased from the first visit (34.1%) to the second visit (24.4%) for the 41 patients who completed 2 visits. B-SITC scores of the first-visit hyposmia participants increased significantly at the second visit (5.29 ± 2.02 to 8.29 ± 2.40; n = 14, P = 0.001). Severe cases tended to recover less than common cases.

Conclusions

Hyposmia was present in up to one-third of COVID-19 patients after about 3 months from disease onset. Notable recovery of olfactory function was observed at a next 5-weeks follow-up. Clinical severity had little influence on olfactory impairment and recovery.

中文翻译：

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2019 冠状病毒病患者长期康复后残留的嗅觉功能障碍

介绍

嗅觉减退是 COVID-19 患者最常见的症状之一。以前的研究主要在疾病的早期阶段描述了这个问题。由于嗅觉障碍可能表明神经系统退化，我们通过评估 COVID-19 患者恢复后期的嗅觉减退来研究永久性嗅觉损伤的可能性。

方法

95 名患者在疾病发作 16 周后接受了汉语简短气味识别测试 (B-SITC) 和嗅觉减退量表 (HRS) 的评估。五周后，41 名患者接受了 B-SITC 的重新测试。

结果

在第一次就诊时，分别有 26/82 (31.7%) 和 22/95 (23.2%) 的参与者通过 HRS（HRS 评分≤22）和 B-SITC（B-SITC 评分 <8）确定了嗅觉减退。在疾病发作后 14-15 周、16-17 周和≥18 周后进行 B-SITC 的患者的嗅觉减退率分别为 7/25 (28%)、8/35 (23%) 和 7/35 ( 20%)，这表明随着恢复时间的延长，嗅觉有改善的趋势。对于完成 2 次就诊的 41 名患者，从第一次就诊 (34.1%) 到第二次就诊 (24.4%)，低血糖百分比下降。第一次就诊时嗅觉减退参与者的 B-SITC 评分在第二次就诊时显着增加（5.29 ± 2.02 至 8.29 ± 2.40；n = 14，P = 0.001）。严重病例的康复率往往低于普通病例。

结论

发病后约 3 个月后，多达三分之一的 COVID-19 患者出现低血症。在接下来的 5 周随访中观察到嗅觉功能的显着恢复。临床严重程度对嗅觉障碍和恢复几乎没有影响。