When fever, dizziness point to something more

Medical Mysteries is a series that spotlights rare diseases or unusual conditions.

Small fibre neuropathy patient Louisa Lim (centre) with her doctors Amanda Chan and Kewin Siah.

Published Oct 11, 2026, 05:00 AM

Updated Oct 11, 2026, 05:00 AM

Tan Zi Ting and Louisa Lim both had years of unexplained symptoms before doctors diagnosed small fibre neuropathy, or SFN, after detailed specialist tests.

SFN can cause varied symptoms, normal standard tests, and serious effects like pain, brain fog, bowel problems and heart rhythm issues. Doctors say it may be more common after Covid-19.

Treatment helped both women, but life changed greatly. Lim stopped work and uses a walking aid, while Tan is studying medicine and hopes to help other patients.

SINGAPORE - Tan Zi Ting was just six months old when she began experiencing repeated episodes of intestinal obstruction – blockage that prevents food or liquid from passing through the small or large intestine – in addition to other issues such as feeding difficulties and persistent constipation.

When she was taken to hospital, doctors told her parents that she had slow gut motility, referring to muscle movements within the gastrointestinal tract that move food through the digestive process.

The 23-year-old told The Straits Times that over the years her symptoms expanded to include a variety of ailments such as nausea, vomiting and high fevers, often requiring medical intervention.

Her condition meant she could not participate in activities such as physical education classes in school and going out with friends. She sometimes had to miss out on school entirely.

“Since it was there all my life, I kind of thought it was normal,” she said.

When Tan was 13 however, the obstructions became more intense, to the point that she could not walk when they occurred, resulting in her missing more than 40 days of school.

“I think that was when we realised that something was severely wrong, because it wasn’t just something that I could push through anymore,” she said.

Another patient, Louisa Lim began experiencing a persistent fever in 2021, shortly after getting married.

While tests showed it was not Covid-19, doctors were unable to determine the cause of her consistently high body temperatures, which reached temperatures of around 39 deg C for months on end, the 34-year-old said.

They diagnosed it only as a pyrexia, or fever, of unknown origin, she recalled, adding that other symptoms – including pain, dizziness and a burning sensation across her back – soon emerged, though tests and scans were unable to provide a cause.

“I was wondering, if my fever is a way of my body telling me something, then what is it?” said Lim, who was working in sales at the time.

Diagnosis and relief

Previously undergoing paediatric care at KK Women’s and Children’s Hospital, in 2021 Tan, who turned 18 that year, decided to continue her treatment at the National University Hospital (NUH).

At NUH Kewin Siah – a senior consultant with the hospital’s gastroenterology and hepatology division – worked together with Amanda Chan, a senior consultant from the neurology division, and others from different specialities to piece together the various symptoms Tan was facing in order to better understand her condition.

In 2021 Tan was diagnosed with small fibre neuropathy (SFN), a form of peripheral neuropathy – referring to conditions where nerves beyond the brain and spinal cord are damaged or dysfunctional.

Symptoms are varied and can be vague, and include painful tingling or burning sensations in the hands and feet, as well as heart palpitations and numbness.

The following year, following a clinical assessment and confirmatory skin biopsy, Lim was also found to have SFN.

She described the diagnosis as a relief.

“To finally know what it is meant I could get treatment,” she said.

As only small nerves in the body are affected, tests for large nerve fibres or the central nervous system can often appear normal, said the neurologist.

“It’s very hard to diagnose because not everybody has the access to these small fibre tests, and at the same time, it’s a relatively newly defined condition,” Chan added .

Siah said that SFN can often be identified only by piecing together the various symptoms a patient may be facing.

“Unless you think about it and put the symptoms together, a lot of patients won’t be getting the right diagnosis,” he said.

Chan noted that while current medical literature suggests that SFN is rare – affecting up to 50 per 100,000 people – its prevalence has gone up since the Covid-19 pandemic, with some studies suggesting anywhere between 25% to 50% of those with long Covid have the condition.

“It’s actually much more common than we think,” Chan said.

She added that this could be a result of the immune system going into overdrive when responding to an infectious disease and attacking the small nerve fibres as a result.

Lim said though she used to be very active – frequenting the gym up to twice a day – her condition put a stop to her physical activity, and she now relies on a walking aid to get around.

She was originally treated with oral medication to manage her pain, later progressing to intravenous immunoglobulin (IVIG) therapy, which involves the infusion of antibodies from healthy donors.

Though IVIG provided relief, the frequency of infusions was disruptive and its effects short-lived.

Lim said the disruptive nature of her treatments, coupled with brain fog, made it difficult for her to concentrate on her job and she opted to stop working.

In 2023, she was started on rituximab – a targeted immune therapy used to treat certain autoimmune diseases and cancers – which helped improve her condition, though her symptoms gradually return between treatment cycles.

For Tan, Siah oversees the severe constipation caused by her condition, working with the colorectal surgery team to develop a treatment plan, which improved her bowel function over time.

Small fibre neuropathy patient Tan Zi Ting in the hospital in April after her enteral tube revision surgery. PHOTO: COURTESY OF TAN ZI TING

Small fibre neuropathy patient Tan Zi Ting in the hospital in April after her enteral tube revision surgery.

PHOTO: COURTESY OF TAN ZI TING

Both doctors are also contributing to research on how SFN is treated and understood.

Siah said that while Tan and Lim are faring relatively well, not all those with SFN are in a similar position, adding that up to 20% of patients “don’t do that well at all”.

Chan noted that in severe cases, the symptoms of SFN could including cardiovascular dysautonomia – a nervous system disorder which results in irregular heart rate or heart rhythms – which could lead to death.

Lim hopes to eventually return to her previous line, which she described as “quite fun” as she frequently travelled for work, though she understands her condition might necessitate something less hectic.

“I’m going to manage my expectations,” she said.

For Tan, learning more about her condition made her passionate about the science behind it, and she is now studying medicine at the University of New South Wales in Sydney, Australia.

She hopes to eventually specialise in gastroenterology, and in November will return to Singapore for an attachement at NUH.

“I think my condition gave me a very strong sense of purpose to be a doctor who shows patients that there is life beyond their diagnosis,” she said.

Zhaki Abdullah is a correspondent at The Straits Times. He is on the health beat, in addition to occasionally covering science, environmental, tech and Muslim affairs issues.

ST Medical Mysteries

National University Hospital

《医学谜案》是一档聚焦罕见疾病或不寻常病症的系列节目。

小纤维神经病患者 Louisa Lim（中）与她的医生 Amanda Chan 和 Kewin Siah 合影。

发布于2026年10月11日 上午5:00

更新于2026年10月11日上午5:00

谭子婷和路易莎·林都曾出现过多年的不明症状，之后经过详细的专科检查，医生才诊断出她们患有小纤维神经病（SFN）。

小纤维神经病变 (SFN) 可引起多种症状，包括常规检查结果正常，以及疼痛、脑雾、肠道问题和心律失常等严重后果。医生表示，新冠肺炎后 SFN 的发生率可能更高。

治疗对两位女性都有帮助，但生活也发生了巨大变化。林女士停止了工作，需要借助助行器行走，而谭女士则正在攻读医学学位，希望将来能够帮助其他患者。

新加坡——谭子婷只有六个月大的时候就开始反复出现肠梗阻——这种阻塞会阻止食物或液体通过小肠或大肠——此外，她还存在喂养困难和持续便秘等其他问题。

当她被送往医院时，医生告诉她的父母，她患有肠道蠕动缓慢，指的是胃肠道内推动食物通过消化过程的肌肉运动。

这位 23 岁的女子告诉《海峡时报》，多年来，她的症状不断加重，出现了恶心、呕吐和高烧等多种疾病，经常需要医疗干预。

她的病情意味着她无法参加学校的体育课和与朋友外出等活动。她有时甚至不得不完全缺课。

“因为它一直都在那里，所以我以为这是正常的，”她说。

然而，当谭13岁时，这些障碍变得更加严重，以至于发生障碍时她无法行走，导致她缺课超过40天。

“我想那时我们才意识到事情非常不妙，因为我再也无法勉强应付下去了，”她说。

另一名患者 Louisa Lim 在 2021 年结婚后不久开始出现持续发烧症状。

这位34岁的女子表示，虽然检测结果显示她并非感染了新冠肺炎，但医生们仍无法确定她持续高烧的原因，她的体温连续数月保持在39摄氏度左右。

她回忆说，医生只诊断为不明原因的发热，并补充说，其他症状——包括疼痛、头晕和背部灼烧感——很快出现，但检查和扫描都无法找到病因。

“我当时就在想，如果发烧是我的身体在告诉我什么，那到底是什么呢？”当时从事销售工作的林说道。

诊断与缓解

此前一直在KK妇女儿童医院接受儿科治疗的谭女士，在2021年年满18岁时，决定在新加坡国立大学医院（NUH）继续接受治疗。

在新加坡国立大学医院，医院胃肠肝病科的高级顾问谢克文与神经科的高级顾问陈阿曼达以及其他不同专业的医生一起，将谭女士面临的各种症状拼凑起来，以便更好地了解她的病情。

2021 年，谭被诊断出患有小纤维神经病 (SFN)，这是一种周围神经病——指的是大脑和脊髓以外的神经受损或功能障碍的疾病。

症状多种多样，可能比较模糊，包括手脚疼痛、刺痛或灼烧感，以及心悸和麻木。

次年，经过临床评估和确诊性皮肤活检，林也被确诊患有小纤维神经病。

她形容确诊结果让她如释重负。

“终于知道这是什么病了，意味着我可以接受治疗，”她说。

神经科医生说，由于只有体内的小神经受到影响，因此对大神经纤维或中枢神经系统的检查结果通常可能显示正常。

“这种疾病很难诊断，因为不是每个人都能进行这些小纤维检测，同时，它也是一种相对较新的疾病，”陈补充道。

Siah表示，SFN通常只能通过将患者可能面临的各种症状拼凑起来才能确定。

他说：“除非你仔细思考并将症状联系起来，否则很多患者将无法得到正确的诊断。”

Chan指出，虽然目前的医学文献表明SFN很罕见——每10万人中最多只有50人患病——但自新冠肺炎疫情以来，其患病率有所上升，一些研究表明，25%到50%的新冠长期患者患有这种疾病。

“实际上，这种情况比我们想象的要普遍得多，”陈说。

她补充说，这可能是由于免疫系统在应对传染病时过度活跃，从而攻击了细小的神经纤维。

林女士说，虽然她以前非常活跃——每天去健身房多达两次——但她的病情使她停止了体育活动，现在她依靠助行器出行。

她最初接受口服药物治疗以控制疼痛，后来发展到静脉注射免疫球蛋白 (IVIG) 疗法，该疗法涉及输注来自健康捐献者的抗体。

虽然静脉注射免疫球蛋白可以缓解症状，但输注的频率令人烦恼，而且其效果短暂。

林女士表示，治疗带来的干扰，加上脑雾，让她难以集中精力工作，因此她选择停止工作。

2023 年，她开始接受利妥昔单抗治疗——这是一种用于治疗某些自身免疫性疾病和癌症的靶向免疫疗法——这帮助改善了她的病情，尽管在治疗周期之间她的症状会逐渐复发。

对于谭来说，西亚负责治疗她因病情引起的严重便秘，并与结直肠外科团队合作制定治疗方案，随着时间的推移，她的肠道功能得到了改善。

小纤维神经病患者谭子婷四月份在医院接受肠内营养管修复手术后。照片由谭子婷提供

小纤维神经病患者谭子婷于四月在医院接受了肠内管修复手术。

照片：由谭子婷提供

这两位医生也都在为小纤维神经病（SFN）的治疗和理解方面的研究做出贡献。

Siah表示，虽然Tan和Lim的情况相对较好，但并非所有患有SFN的人都处于类似的境地，并补充说，高达20%的患者“情况非常糟糕”。

Chan 指出，在严重病例中，SFN 的症状可能包括心血管自主神经功能障碍——一种导致心率或心律不齐的神经系统疾病——这可能导致死亡。

林女士希望最终能重返她之前的行业，她形容那份工作“很有趣”，因为她经常出差，不过她也明白，她的身体状况可能需要一些不那么忙碌的工作。

“我会调整好自己的期望值，”她说。

对谭来说，更多地了解自己的病情让她对背后的科学产生了浓厚的兴趣，她现在正在澳大利亚悉尼的新南威尔士大学学习医学。

她希望最终能专攻肠胃病学，并将于 11 月返回新加坡，在新加坡国立大学医院进行实习。

“我认为我的病情让我有了非常强烈的使命感，要成为一名医生，向患者展示，除了诊断结果之外，生活依然精彩，”她说。

扎基·阿卜杜拉是《海峡时报》的记者。他主要负责健康新闻报道，偶尔也报道科学、环境、科技和穆斯林事务等议题。

ST 医学谜案

国立大学医院