Can Lyme Disease Cause Small Fiber Neuropathy? Burning Nerve Pain Explained
Lyme disease may affect the smallest sensory and autonomic nerves.
Symptoms include burning pain, tingling, allodynia, and dizziness despite normal nerve tests.
Early recognition may help guide diagnosis and treatment.
Can Lyme disease cause small fiber neuropathy? Yes. Small fiber neuropathy has been described in some patients with Lyme disease and may contribute to burning pain, tingling, numbness, sensitivity to touch, dizziness, and autonomic dysfunction. Because small fiber neuropathy affects nerves that are not evaluated by routine EMG or nerve conduction studies, patients may experience severe symptoms despite normal neurologic testing.
Small fiber neuropathy has become an important area of Lyme disease research because it may explain why some patients continue to experience burning pain, numbness, dizziness, and autonomic symptoms despite normal neurologic testing.
Researchers have also reported small fiber neuropathy following COVID-19 infection, supporting the broader observation that certain infections may trigger persistent injury involving sensory and autonomic nerve fibers. Although Lyme disease and COVID-19 are distinct illnesses, both have been associated with neuropathic symptoms in selected patients.
For a broader discussion of neurologic complications, see our Neurologic Lyme disease hub and our overview of Autonomic dysfunction in Lyme disease.
What Is Small Fiber Neuropathy?
Small fiber neuropathy (SFN) is a disorder affecting the body’s smallest sensory and autonomic nerve fibers. These nerves transmit pain and temperature sensations while also regulating involuntary body functions such as heart rate, blood pressure, sweating, digestion, and bladder function.
Unlike large-fiber neuropathies, small fiber neuropathy often cannot be detected by routine nerve conduction studies or electromyography (EMG). Instead, diagnosis may require specialized testing such as a skin biopsy measuring intraepidermal nerve fiber density (IENFD) or autonomic function testing.
Patients with Lyme disease may develop symptoms involving both the sensory and autonomic nervous systems, making small fiber neuropathy an important consideration when routine neurologic testing is unrevealing.
Small Fiber Neuropathy in Lyme Disease
Small fiber neuropathy affecting both sensory and autonomic nerves has been described in patients with Lyme disease.
Novak and colleagues found evidence of small fiber neuropathy in patients with post-treatment Lyme disease syndrome, suggesting that nerve fiber loss may contribute to persistent sensory symptoms and autonomic dysfunction in some individuals.
These findings support growing interest in the relationship between neuropathy, autonomic dysfunction, and persistent Lyme disease symptoms.
Although not every patient with persistent Lyme disease develops small fiber neuropathy, these studies suggest it may represent one mechanism underlying chronic sensory symptoms and autonomic dysfunction in a subset of patients.
Learn more about Autonomic dysfunction, small fiber neuropathy, and Lyme disease.
Case Report: Burning Pain Improved After Lyme Disease Treatment
In their report, “Resolution of Pain in the Absence of Nerve Regeneration in Small Fiber Neuropathy Following Treatment of Lyme Disease,” Feuer and Alaedini described an 83-year-old woman with a four-year history of diffuse burning pain involving her face, arms, and legs, accompanied by painful muscle spasms.
Testing confirmed Lyme disease.
The patient received a 40-day course of oral antibiotic therapy and experienced complete resolution of her neuropathic pain.
This case suggests that small fiber neuropathy may, in selected patients, reflect an infection-associated inflammatory process rather than irreversible nerve injury.
Although individual case reports cannot establish cause and effect, they illustrate that neuropathic symptoms may improve following treatment in carefully selected patients.
Why Lyme Disease May Cause Burning Nerve Pain
The exact mechanism by which Lyme disease contributes to small fiber neuropathy remains under investigation.
Several mechanisms have been proposed:
- Inflammation affecting small sensory nerve fibers
- Immune-mediated injury following infection
- Autonomic nerve involvement affecting blood vessels and internal organs
- Persistent neuroinflammation that amplifies pain signaling
Small nerve fibers are responsible not only for pain and temperature sensation but also for regulating involuntary body functions. Damage to these fibers may explain why some Lyme disease patients experience both burning pain and autonomic symptoms.
Additional research is needed to determine which mechanisms predominate and why only some patients appear to develop small fiber neuropathy following infection.
Symptoms associated with autonomic involvement are discussed in greater detail in our article on Autonomic dysfunction in Lyme disease.
Common Symptoms of Small Fiber Neuropathy
Symptoms vary depending on which sensory or autonomic fibers are involved.
Patients commonly describe:
- Burning pain in the feet or hands
- Tingling or “pins and needles”
- Numbness
- Electric shock sensations
- Pain from light touch (allodynia)
- Temperature sensitivity
- Reduced sweating
- Dizziness upon standing
- Heart rate or blood pressure fluctuations
- Digestive problems or constipation
These symptoms may fluctuate over time and frequently overlap with broader neurologic manifestations of Lyme disease.
Patients may also experience exercise intolerance, lightheadedness, brain fog, and other symptoms related to autonomic dysfunction.
Why EMG and Nerve Conduction Studies Are Often Normal
Many patients become frustrated after being told their neurologic testing is “normal” despite persistent burning pain or numbness.
Routine nerve conduction studies and electromyography (EMG) primarily evaluate large nerve fibers.
Small fiber neuropathy affects the smallest sensory and autonomic nerves, which are generally not detected by these tests.
As a result, patients may have significant neuropathic symptoms despite completely normal EMG and nerve conduction study results.
When symptoms strongly suggest small fiber neuropathy, clinicians may consider specialized testing such as:
- Skin biopsy measuring intraepidermal nerve fiber density (IENFD)
- Autonomic reflex testing
- Quantitative sudomotor axon reflex testing (QSART)
- Tilt-table testing when autonomic dysfunction is suspected
These specialized studies may identify abnormalities that routine neurologic testing cannot detect.
Learn more about Lyme disease neuropathy.
Small Fiber Neuropathy After COVID-19
Small fiber neuropathy has also been reported following COVID-19 infection.
Shouman and colleagues described patients who developed neuropathic symptoms after SARS-CoV-2 infection.
- A 52-year-old man developed burning pain beginning in his feet that progressed to his knees, accompanied by imbalance, falls, and allodynia.
- A 67-year-old woman experienced worsening neuropathy, persistent burning pain, and occasional orthostatic symptoms months after COVID-19.
Allodynia refers to pain produced by stimuli that normally are not painful, such as light touch.
The investigators suggested that COVID-19 may have triggered or worsened small fiber neuropathy in susceptible individuals. Because the study was observational, however, it could not establish a direct causal relationship.
Although Lyme disease and COVID-19 are distinct illnesses, both have been associated with persistent neuropathic and autonomic symptoms in some patients. Ongoing research may improve understanding of how infections contribute to small fiber neuropathy.
For more, see our article on Long COVID and Lyme disease.
Can Small Fiber Neuropathy Improve?
Recovery varies depending on the underlying cause, the severity of nerve injury, and how quickly treatment is initiated.
Some patients experience meaningful improvement in burning pain and autonomic symptoms after treatment, while others continue to have persistent symptoms that require long-term management.
Although nerve regeneration may be slow or incomplete, symptom improvement can occur even when objective nerve fiber measurements remain abnormal.
Early recognition of small fiber neuropathy may improve the opportunity for appropriate evaluation, treatment, and symptom management.
Frequently Asked Questions
Can Lyme disease cause small fiber neuropathy?
Yes. Small fiber neuropathy has been described in some patients with Lyme disease and may contribute to burning pain, tingling, numbness, allodynia, dizziness, and autonomic dysfunction. Specialized testing may be required because routine EMG and nerve conduction studies are often normal.
Can small fiber neuropathy improve after Lyme disease treatment?
Some patients experience meaningful improvement in neuropathic symptoms following treatment. Published case reports have documented complete resolution of burning pain in selected individuals, although outcomes vary depending on the underlying cause and duration of symptoms.
Can COVID-19 trigger small fiber neuropathy?
Yes. Small fiber neuropathy has also been reported following COVID-19 infection. Researchers believe certain infections may trigger inflammatory or immune-mediated injury involving small sensory and autonomic nerve fibers.
Why are my EMG and nerve conduction studies normal?
Routine nerve conduction studies and EMG primarily evaluate large nerve fibers. Small fiber neuropathy affects much smaller sensory and autonomic fibers that generally are not detected by these tests.
What symptoms are common in small fiber neuropathy?
Patients commonly report burning pain, tingling, numbness, electric shock sensations, sensitivity to touch (allodynia), dizziness, orthostatic intolerance, digestive symptoms, and other signs of autonomic dysfunction.
Clinical Takeaway
Small fiber neuropathy is a recognized neurologic complication that has been reported in both Lyme disease and COVID-19.
I have evaluated patients with burning pain, tingling, numbness, dizziness, orthostatic intolerance, and other autonomic symptoms whose routine neurologic testing was normal. In selected cases, recognizing the possibility of small fiber neuropathy helped explain persistent symptoms and guided further neurologic evaluation.
Because routine EMG and nerve conduction studies often miss small fiber involvement, clinicians may need to consider specialized testing when symptoms strongly suggest sensory or autonomic neuropathy.
Recognizing small fiber neuropathy may help prevent misdiagnosis and lead to a more comprehensive neurologic evaluation in patients with persistent Lyme disease symptoms.
Related Articles
These articles explore neuropathy, autonomic dysfunction, and other neurologic complications associated with Lyme disease.
Autonomic Dysfunction, Small Fiber Neuropathy, and Lyme Disease
Could Lyme Disease Be Causing Neuropathy?
Persistent Lyme Disease Mechanisms
Neurologic Lyme Disease
Long COVID and Lyme Disease
References
- Novak P, Felsenstein D, Mao C, Octavien NR, Zubcevik N. Association of Small Fiber Neuropathy and Post-Treatment Lyme Disease Syndrome. PLoS One. 2019;14(2):e0212222.
- Feuer N, Alaedini A. Resolution of Pain in the Absence of Nerve Regeneration in Small Fiber Neuropathy Following Treatment of Lyme Disease. Neurology. 2013;80(Suppl):P06.228.
- Shouman K, Vanichkachorn G, Cheshire WP, et al. Autonomic Dysfunction Following COVID-19 Infection: An Early Experience. Clin Auton Res. 2021;31(3):385-394.
- Oaklander AL, Nolano M. Scientific Advances in and Clinical Approaches to Small-Fiber Polyneuropathy. JAMA Neurol. 2019;76(11):1240-1251.
- Halperin JJ. Neurologic Manifestations of Lyme Disease. Continuum (Minneap Minn). 2020;26(5):1194-1222.
Dr. Daniel Cameron, MD, MPH
Lyme disease clinician with over 30 years of experience and past president of ILADS.
Symptoms • Testing • Coinfections • Recovery • Pediatric • Prevention
My original Lyme symptom was muscle inflammation with terrible pain in head, neck and shoulder. After months of severe pain, I was finally put on Steroids to manage what doctors thought was Polymyalgia Rheumatica (PMR). Oddly enough, the Rheumatologist took a Lyme test and it was totally CDC, all bands positive. Once, I started Doxy, and then a round of IV ceftriaxone, I developed terrible nerve pain, numbness on my left side from headaches, face, neck shoulder, back, sacro and left leg.
Unfortunately, all the antibiotics have not relieved this neuropathy or the pain on my left side. Had Shingles twice since Lyme diagnosis which may be causing some nerve pain as well.
Somehow, I tested positive again for Lyme and Babesia last month – no bite, no rash. I’m on second round of Doxy, Azithromycin and Atovaquone. This new treatment has intensified the nerves and I’m absolutely miserable. Maybe herxing?
Has anyone had nerve pain that still persists after antibiotic treatment? Treatment and/or Detox?
That is exactly what I am dealing with. None of my MD’s even mentioned Lyme when they were examining me. The tingling started a bit and when it was evident all the time, I got a referral to the neurologist. He called it sensory neuropathy. Said to come back in 6 months (to see if it was getting worse or not). It is continual and no, I am not going back as I can’t see how they will have a fix anyway.
Yes, my daughter is dealing with severe neuropathic pain that started during treatment with antibiotics and still last after finishing. She has been prescribed with gabapentin and lipoic acid for the pain. Also she is being tested for SFN and doctors are considering IVIG as well. She still is positive for Lyme on the bands but not with the PCR. Doctors (neuro & reuma) are not sure if continuing antibiotics will benefit her at all. How long a patient should receive antibiotics when PCR is negative but bands are still positive, considering the side effects?
I often have Lyme disease patients with a negative PCR and neuropathy who do well with antibiotic treatment. I have some patients who fail antibiotic treatment for neuropathy. I ask my patients to continue working with their neurologist if their neuropathy persists. Some have benefited from IVIG.
Hi dr Cameron,
I have first the diagnose Sarcoidose, later small fiber neuropathy and 8 years later TBD.
The TBD is a big struggle in the lyme world.
Iam extremely tired with pain also.
Lot of brainfog.
Muscle pain and bone pain.
Sleap problems.
Tninitus.
Dry mouth and tong. Burn mouth syndrom.
Also are mine Interleukine very high
Best regards,
Ed
When small nerve fibers are damaged they become hyperexcitable and you’ll probably find that many antibiotics can cause flare ups in nerve symptoms. While I don’t have lyme (as far as I’m aware), I did develop neuropathy, most likely from B12 deficiency. When I went to treat a UTI, I was unable to tolerate Trimethoprim or Doxycycline as they’d cause severe nerve pain, burning, numbness, tingling, shooting pains. I had no issues at all with these antibiotics prior to developing SFN. Once I stopped the antibiotics , the nerve pains would mostly go away. It seemed that the antibiotics simply unmasked nerve damage, but without a trigger, the level was under the threshold that was obvious. So the strategy was then to allow my nerves to heal somewhat and then try again 9 months later while I treated it naturally to suppress the infection.
I was finally able to tolerate Trimethoprim after 9 months, especially when I added R lipoic acid to my regimen. It seemed that ALCAR, Benfotiamine, Magnesium Glycinate did not prevent the burning pain completely, but it was still around a 3-4 out of 10. Once I added the ALA, it went to a 0 and tolerated Trimethoprim for 2 months. Unfortunately the bacteria eventually become resistant it seems.
I was also getting weird reactions to even things like glycerol, which I guess because it may alter osmolality of the cells and somehow leads to increased nerve pain. But I can toleate this much better now. Also, even Hiprex would cause nerve pain and that has no neurotoxicity that has been documented.
I still have not tried Doxycycline again but that is probably what I will need to take. So I’m hoping my nerves have repaired enough to be less hyperexcitable and the R lipoic will help. I had no idea that I had B12 deficiency when I first tried Doxy. Or that R Lipoic was so helpful.
Whether or not it is a psuedoexacerbation of the the SFN, I am unsure. Hypersensitive nerves can react to even benign things. So it’s not always because of a herx reaction due bugs (in the case of lyme) dying off.
Do many lyme patients just try to tolerate the nerve pain and work through the course? I have wondered how some people with SFN have no issues with antibiotics. Maybe there is genetic differences in sodium ion channel genes. Hopefully new targeted therapies that reduce hyperexcitability by targeting thse Nav genes (some in trials now I think) will enable patients to complete treatment without the serious nerve side effects.
can sfn remit with antibiotics
In 1990, Logigian and colleagues described axonal sensory neuropathy in Lyme disease. some of their patients improved. I have seen some patients whose SFN has improved with antibiotics.
Hi,
I have suffered with small fiber neuropathy for 16 years. In spite of my pain meds, being the only thing that has given me any relief, I still hurt. My pain worsened for months and I blamed it on SFN ect…Then I couldn’t walk, developed a skin infection with bad neck pain. My Dr. tested me for Lyme disease. I was surprised It came back positive! They put me on an antibiotic for 3 weeks. I am only 1 week into taking my antibiotics. I am still in so much leg and foot pain walking is almost impossible! I feel really hopeless! Even at it’s worse with SFN I could walk! Will this ever get better?