Newly diagnosed small fiber neuropathy - muscle twitching and mottling

I also have type I diabetes. I’ve seen two neurologists, due to some of the symptoms you describe. I was recently diagnosed with Vitamin B12 deficiency. My neurologist believes it has caused my symptoms. In light of this, I caution those with symptoms like mine to get tested. It can cause neurological symptoms.

Do you know what tests his neurologist did?

I had skin issues, but not mottling like you describe. I hope that your son can find help.

I have had polyneuropathy in my arms and legs for 9 years, mostly loss of feeling and tiring out the nerves if I use them too much (woodturning, gardening, close work). Mine is likely associated with celiac (gluten) and/or MGUS (plasma cell disorder) or hypothyroidism. It hasn't progressed I'm not on meds. It would be good to get a full medical eval, to see if your son has other problems. When you have one autoimmune problem, you tend to collect others. ResearchGate has peer reviewed papers on small fiber and other neuropathies.

Thanks for the reply @celia16. Regarding tests, at this time, he's had a lot of blood work and he's scheduled for a Sjogrens test (lip biopsy). Also, I know they looked at B12 levels and they were fine. I hesitate to have him have the lip biopsy since he doesn't seem to have Sjogrens symptoms (no dry eyes, no overall dryness). No root cause has been found at this time.

Glad his B12 is good. I hesitate to have a lip biopsy too. My neurologist ordered an array of blood tests in prep for my Rheumatologist visit. Sjogrens suspected, though I only have dry eye. Positive ANA though.

What type of insulin treatment does your son use?

Good luck with your Rheumatologist visit! He's using a Medtronic 780G and a guardian 4 sensor. He recently switched insulin but I can't remember which brand.

Thanks @kayabbott, I'm trying to get him into another neurologist to get a full medical eval. His present neurologist just wants to give him pain meds.

Me too! I love my Medtronic 780! It helps me so much.

I have been fortunate to not need pain meds yet, though I have prescriptions.

The mottling you describe sounds like livedo reticularis, a manifestation of bloodvessel instability associated with autoimmune diseases. I am curious why the lip biopsy was recommended if he has no symptoms of Sjogrens. There must have been some autoimmune antibodies that showed up on his blood tests. The mottling is caused by spasm in the muscles of the small arteries in the skin. It often shows up after showering. I would take pictures of it and have it confirmed by a dermatologist. You can see pictures of it online if you do a search for images. It’s not dangerous, just looks weird.

Hello @slkanowitz and thanks for your input. There were no autoimmune antibodies or any other indicators of Sjogrens in the blood work. The doctor said it's not probable; however, it was possible that the blood work would be negative for Sjogrens but the lip biopsy would show positive. To re-iterate, he does not have any dry eye issues so (in my opinion) it's a waste of time.
My type 1 diabetic son is having 'non-length dependent' neuropathy (burning and numbness all over his body - mostly in the legs, feet, hands, face, chest, and back). He does not need meds yet; however, every week he seems a little worse, and we have no idea what's going on. Have you ever heard of this course of neuropathy? Thanks.

Hi kaphilmore,

I read your post because I get weird mottling (my doctors are not concerned about it), too.

I just want to say that I think you are being a great parent! It's so hard to deal with all of the medical stuff, and, sadly, it's really necessary to get really well informed, especially when the symptoms are uncommon. So, yay you! Way to go! Pat yourself on the back! Give yourself a lot of credit! Take a second out of your worry to feel good about being a good parent!
Blessings and good luck to you and your son!