Small Fiber Neuropathy—definitive test available?

[Jessis]

I was reading up on this and it seems to me (if I infer correctly) that a typical diagnosis of Small Fiber Neuropathy is based on the process of elimination when running other EMG. In my situation, I have differing opinions. Some physicians believe Lumbar spinal compression is the cause of my tingling, burning, and sharp pain when (mostly sleeping).

I have GI issues and one (retired) physician says GI issues such as Ulcerative colitis are not auto-immune diseases. but I also have what appears to be Gottron papules (Dermatomyositis) and cheiropompholyx (dyshidrotic eczema) which really flares up whenever I have any issue with my gut such as eating fresh fruit or vegetables.

[Sara_MHModerator]

Hello, thank you for your question. You are correct that there is no definitive test for this issue.  They do EMG and nerve conduction studies to help in the process of diagnosis. Skin biopsies are used to confirm loss of cutaneous nerve innervation as part of the process. Diagnosis therefore tends to be based on characteristic symptoms and is most often confirmed with a skin biopsy demonstrating reduced intraepidermal nerve fiber (IENF) density. Through this means, they find nerve density reduced in patients with small fiber neuropathy and in particular in the Intraepidermal nerve fiber.  In SFN, this can be reduced 65 to 90%. They also take into account where the neuropathy  is and automatic nervous system involvement. Underlying disease is considered such as diabetes. Fibromyalgia is also often commonly related to SFN.

To date, they do not know the exact cause of ulcerative colitis.  I am wondering if your doctor is not from the era where ulcerative colitis was always blamed on stress, diet, etc.  Today we know that it also can be autoimmune related.  UC happens when the autoimmune system attacks healthy tissue in the gut which then causes inflammation in the gut leading to symptoms of UC.

Have you been diagnosed with Dermatomyositis and Gottron papules?  This can involve not just the rash but progressive muscle weakness and on both sides of your body starting at the trunk moving out. This may be an area to talk to a doctor about as peripheral nerve involvement in dermatomyositis   has been known as neuromyositis.  Not all doctors will correlate these two things but there is literature to support it. Here is a study that you can copy and paste into your browser to to read about this. https://pubmed.ncbi.nlm.nih.gov/20229079/

Hopefully you will have a new doctor or specialist that you can receive a proper diagnosis and treatment with.

[Jessis]

Hi Sara, thank you for the very informative reply. My Gastroenterologist "diagnosed" me with Gottron papules on my last visit, just before his retirement. He was quite frank and said the medical system (in Canada) has failed me. His replacement has yet to contact me regarding the tests he ordered.

Googling the term Gottron papules linked it to Dermatomyositis which I assumed are one in the same.  There certainly seems to be some muscle weakness (in my opinion) but nothing was shown in a partial EMG. I've been experiencing a lot of nerve pain when sitting, lying down, especially when lying down on my left side. The nerve pain is much worse on the left.

There are different opinions what's going on. Its' quite frustrating. One physician thinks the nerve pain my be related to lumbar compression of the spine whist another doesn't think there's any peripheral neuropathy, another is like "umm" I don't know what to think.

But given the nerve pain and the pink knuckles plus cheiropompholyx  which always flares "way up" when I have gut issues and eating raw produce I'm thinking there is something really wrong here. The current tests including Fecal calprotectin are high (65) but in the "inconclusive range".

My muscle enzymes (blood tests) have always been high and my GP has always dismissed that. The most current blood work show the following:

Protein Electrophoresis, Total Protein [high normal] 74/80
Alpha 2 Globulin — 8.7/9
Beta 2 Globulin — 4.8/5
Urine Electrophoresis — Trace albumin (had for long, long time)
Carcinoembryonic Antigen seemed to be normal.
Nuclear Ab Titre normal.