Approximately 10% to 20% of individuals with previous SARS-CoV-2 infection may develop long-COVID syndrome, characterized by various physical and mental health issues, including pain. Previous studies suggested an association between small fibre neuropathy and pain in long-COVID cases. In this case-control study, our aim was to identify small fibre neuropathy in patients experiencing painful long-COVID syndrome. Clinical data, quantitative sensory testing, and skin biopsies were collected from 26 selected patients with painful long-COVID syndrome. We also examined 100 individuals with past COVID-19 infection, selecting 33 patients with painless long-COVID syndrome, characterized mainly by symptoms such as brain fog and fatigue, and 30 asymptomatic post-COVID-19 controls. Demographic and clinical variables were compared among these groups. Among the 26 patients with painful long-COVID syndrome, 12 had skin biopsy and/or quantitative sensory testing abnormalities compatible with small fibre neuropathy. Demographic and clinical data did not differ across patients with small fibre neuropathy, patients with painless long-COVID syndrome, and asymptomatic post-COVID-19 controls. This case-control study showed that approximately 50% of patients experiencing painful long-COVID syndrome had small fibre neuropathy. However, in our patient cohort, this specific post-COVID-19 complication was unrelated to demographic and COVID-19 clinical variables. Approximately half of our sample of patients with painful long-COVID symptoms met diagnostic criteria for small fibre neuropathy.

中文翻译：

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小纤维神经病常常是痛苦的长效新冠综合症的根源。

大约 10% 到 20% 的既往感染过 SARS-CoV-2 的个体可能会出现长期新冠肺炎综合征，其特征是各种身心健康问题，包括疼痛。先前的研究表明，小纤维神经病变与长期新冠病例的疼痛之间存在关联。在这项病例对照研究中，我们的目的是确定经历痛苦的​​长期新冠肺炎综合征的患者是否存在小纤维神经病变。从 26 名选定的患有痛苦的长期新冠肺炎综合征的患者中收集了临床数据、定量感官测试和皮肤活检。我们还检查了 100 名既往感染过 COVID-19 的个体，选择了 33 名患有无痛长期 COVID 综合征的患者，其特征主要是脑雾和疲劳等症状，以及 30 名无症状的 COVID-19 后对照者。对这些组之间的人口统计学和临床​​变量进行了比较。在 26 名患有痛苦的长期新冠肺炎综合征的患者中，有 12 名患者的皮肤活检和/或定量感觉测试异常，与小纤维神经病相符。小纤维神经病患者、无痛长效 COVID 综合征患者和无症状的 COVID-19 后对照患者的人口统计学和临床​​数据没有差异。这项病例对照研究表明，大约 50% 经历痛苦的​​长 COVID 综合征的患者患有小纤维神经病。然而，在我们的患者队列中，这种特定的 COVID-19 后并发症与人口统计和 COVID-19 临床变量无关。在我们的具有长期痛苦的新冠症状患者样本中，大约有一半符合小纤维神经病的诊断标准。