ME/CFS symptoms turned out to be SFN

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I've been dealing with ME/CFS symptoms for close to 2 years now. It wasn't until earlier this year that my doctor found the cause of my symptoms. A punch biopsy revealed small fiber neuropathy. How many of you checked for SFN? I ask because many articles I've been reading lately have been linking SFN to conditions like EDS, Fibromyalgia and ME/CFS.

https://www.healthrising.org/blog/2021/05/06/small-nerve-fiber-snf-energy-chronic-fatigue-syndrome/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4940063/
https://www.verywellhealth.com/small-fiber-neuropathy-may-cause-fibromyalgia-pain-3972935

My symptoms:
air hunger
heaviness sensation in legs
freezing/burning sensation on skin
bug crawling sensation on skin
pins and needles
nausea
bloating
fatigue
exercise intolerance
adrenaline surges before bed

If anyone is experiencing these types of symptoms, it might be worth looking into SFN. In most cases an EMG nerve conduction test will not spot SFN. A punch biopsy is what found mine.
 

JES

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I think SFN is more common than reported in ME/CFS. Recently a study found people with long COVID had nerve fibre loss in the cornea and that this could predict small fiber neuropathy elsewhere in the body (ref).

The tricky bit is to get a diagnosis as most places aren't keen on doing biopsies. They only offered an EMG test for me, which is obviously useless for diagnosing SFN.
 
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I've been dealing with ME/CFS symptoms for close to 2 years now. It wasn't until earlier this year that my doctor found the cause of my symptoms. A punch biopsy revealed small fiber neuropathy. How many of you checked for SFN? I ask because many articles I've been reading lately have been linking SFN to conditions like EDS, Fibromyalgia and ME/CFS.

https://www.healthrising.org/blog/2021/05/06/small-nerve-fiber-snf-energy-chronic-fatigue-syndrome/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4940063/
https://www.verywellhealth.com/small-fiber-neuropathy-may-cause-fibromyalgia-pain-3972935

My symptoms:
air hunger
heaviness sensation in legs
freezing/burning sensation on skin
bug crawling sensation on skin
pins and needles
nausea
bloating
fatigue
exercise intolerance
adrenaline surges before bed

If anyone is experiencing these types of symptoms, it might be worth looking into SFN. In most cases an EMG nerve conduction test will not spot SFN. A punch biopsy is what found mine.
Afaik it’s not necessarily the cause of your symptoms but a common comorbidity … especially when you have POTS
 
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Woah, congrats on finding answers. What treatment(s) are you pursuing? Are you feeling better?
Unfortunately, there isn't much that can be done for SFN at this time. Usually, patients are given drugs like gabapentin, pregabalin, duloxetine, marijuana and opioids. In many cases, the underlying cause of SFN is idiopathic and so far this is the case for me. If you can treat the underlying cause then it might be possible for the SFN to stop progressing but if the underlying cause is unknown or if it's being caused by something that is incurable such as ehlers danlos then the SFN will continue to progress in most cases.
 

hapl808

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That's one of the reasons I didn't pursue muscle biopsies. I felt it had a significant chance to make my symptoms worse, and it seemed unlikely the diagnostic information would be actionable. That's always my personal goal with any testing - will the information gained change my treatment, outcome, etc.
 
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I think SFN is more common than reported in ME/CFS. Recently a study found people with long COVID had nerve fibre loss in the cornea and that this could predict small fiber neuropathy elsewhere in the body (ref).

The tricky bit is to get a diagnosis as most places aren't keen on doing biopsies. They only offered an EMG test for me, which is obviously useless for diagnosing SFN.
Yup, the neurologist did an EMG test on me and it turned out normal so he sent me on my way yet all of my symptoms persisted. I had to pay $1000 out of pocket to see a doctor at the Center for Complex Diseases who believed me and decided to run a punch biopsy test which confirmed SFN.
 

5vforest

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Unfortunately, there isn't much that can be done for SFN at this time. Usually, patients are given drugs like gabapentin, pregabalin, duloxetine, marijuana and opioids. In many cases, the underlying cause of SFN is idiopathic and so far this is the case for me. If you can treat the underlying cause then it might be possible for the SFN to stop progressing but if the underlying cause is unknown or if it's being caused by something that is incurable such as ehlers danlos then the SFN will continue to progress in most cases.
No IVIG trial?
 

katabasis

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IVIG is used for autoimmune SFN. My ANA is normal so the doctors don't think mine is caused by an autoimmune disease.
A test for ANA alone is not sufficient to rule out autoimmune disease. You should also be looking at TS-HDS, FGFR3, antiganglioside antibodies, and maybe also an autoimmune encephalopathy panel, which covers various GPCRs, ion channels, etc. Mayo Clinic does some of these. I have SFN and had a positive antiganglioside antibody test. In many cases this is sufficient to get IVIG should you be interested in it.

However there are also a lot of other things that can result in SFN that should be considered first. The big ones are diabetes/glucose intolerance, Sjogren's disease, and sarcoidosis, but supposedly, infections and toxins can sometimes precipitate SFN.
 
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A test for ANA alone is not sufficient to rule out autoimmune disease. You should also be looking at TS-HDS, FGFR3, antiganglioside antibodies, and maybe also an autoimmune encephalopathy panel, which covers various GPCRs, ion channels, etc. Mayo Clinic does some of these. I have SFN and had a positive antiganglioside antibody test. In many cases this is sufficient to get IVIG should you be interested in it.

However there are also a lot of other things that can result in SFN that should be considered first. The big ones are diabetes/glucose intolerance, Sjogren's disease, and sarcoidosis, but supposedly, infections and toxins can sometimes precipitate SFN.
Thanks for letting me know about these tests. I had no idea there were more ways to check for autoimmune besides ANA. I live in California and I don’t have the best medical insurance. What would be the next steps to take for someone in my position? If one of these tests can prove I have autoimmune then I can be approved for IVIG and potentially get better.
 
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Pyrrhus

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I'm sorry to hear that you have it too. It's not easy living with this disease especially when it has autonomic involvement. Have you found anything that has eased some of the symptoms?
Since my SFN is in my legs and appears to be partly related to circulation issues, I find that keeping my feet raised makes a big difference.

I have a special pillow that I use to elevate my feet:
https://www.amazon.com/dp/B082XKFYLJ?psc=1&ref=ppx_yo2_dt_b_product_details

Hope this helps.
 

katabasis

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Thanks for letting me know about these tests. I had no idea there were more ways to check for autoimmune besides ANA. I live in California and I don’t have the best medical insurance. What would be the next steps to take for someone in my position? If one of these tests can prove I have autoimmune then I can be approved for IVIG and potentially get better.
By far the most important step is to get your doctor on board with wanting to get you IVIG. Having a positive skin punch biopsy is a good start, and with positive blood work for some antibody or another, you're a good candidate for IVIG, but ultimately, your health insurance is very likely to deny you at first. In that case your doctor will need to do a peer-to-peer with your insurance. So, it's important that they are willing to strongly advocate for you to get IVIG.
 

Gingergrrl

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Thanks for letting me know about these tests. I had no idea there were more ways to check for autoimmune besides ANA
ANA is a very general test for autoimmunity and does not tell you whether you are positive or negative for any specific disease. I would get tested for the specific autoantibodies that correlate with SFN: Fibroblast Growth Factor Receptor 3 (FGFR3) and Trisulfated Heparin Disaccharide (TS-HDS) antibodies.

What would be the next steps to take for someone in my position?
I would follow up with your doctor who ordered the skin punch biopsy to discuss the next steps.

If one of these tests can prove I have autoimmune then I can be approved for IVIG and potentially get better.
It really depends on your individual insurance but I have heard of people being approved for IVIG for SFN.