small fiber neuropathy shows only in feet but burning is everywhere
 

Hello to all of you!
Like many of you, my history is long and confusing not only to me but to doctors as well.I just saw the doc that did the skin punch biopsy and it shows yes to sfn in feet but on calf there is none. This is so confusing because ethe very painful burning in my feet is what I feel in my arms, trunk, back, neck. And mouth without pain meds even with them during a flare up. Since 95 I have had balance issues, visual problems, numbness and weakness in my legs, latere pain in muscles and then finally in the skin. Evoked potentials of legs and eyes showed delays in both but mri was clear, B12 deficiency was positive so tentative explaination was possible MS/ Demylenating syndrome. Aas I said oveer the years I developed pain in muscles,fatiguE, many UTI's, reactions to many meds, and finally this god forsaken burning started in my back,lost my voice completely first 2 times, then the burning spread to my arms legs body and feet. Now today I get the results about SFN only in my feet and they don't know why I burn everywhere else. My skin has become wrinkled and dry especially on my arms. My Evoked Potentials on my legs are worse now then every but no delays in my eyes. They are trying me on a drug called methotrexate as steroids were helpful during the initial onset of burning skin. Which scares the heck out of me when I read the side effects, but my question to all of you is do any of you feel this horrible burning all over but have the Skin punch biopsy only reflect SFN in the feet? The burning in my feet is actually less painfull than what I feel all over the rest of my body. Have any of you tried this medicine and did it help? I currently take fentanyl 150 mg patch with 8 mg dilaudid 4-8 hrs. So I am hopeful the new med works and I can lessen the pain meds. I sure appreciate anyone who replies. This is a great site and has been helpful in my quest to find answers. Looking forward to hearingg from you.

Welcome to NeuroTalk:

Can you elaborate on the bolded statement in your post, for us?
Do you know your actual numerical reading for the B12?

You must be in significant pain, based on the fentanyl dose.
Can you tell us what drugs you were taking when this started?

Methotrexate is used for autoimmune diseases. Did you have testing for that too? Was it positive?

I think with time as the nerves dwindle in one area, that spot becomes numb. It is when the nerves are actively being damaged that the burning is felt. So if the biopsy shows loss of nerves in the skin, you will actually feel LESS over time there.

It is important to have some treatment for an inflammatory/autoimmune process because that process can attack the nerves that run your heart and stomach. You don't want THAT to happen at all.

It sounds like your case is pretty complex. And yes, there are and have been many people here who have body-wide burning pain.

You might want to look over the subforum at the top of the page here, there are many informational topics and links to medical sites save there.

Hello MrsD and thank you for your reply! I don't know the numerical reading for the B12 Deficiency. I was just told by my neuro back in 95 that I was extremely low. He felt that the deficiency is what caused the delays in the evoked potentials. I began having b12 injections and over time my vision improved (as did the evp of eyes). However the evps done of my legs improved and decreased which was confusing even to him. The last one done on my legs was June last year and they had worsened and the results of my right leg was significantly worse than the left. The neuro that read the results states that he has no idea why they are delayed.
When I saw the new neuro yesterday (one who performed the skin punch biopsy) he said that the damage done to legs from B12 deficiency is done and won't change. That is odd because they have been changing all along.
He then said that small fiber neuropathy is only on my foot, because the one above on the ankle is fine. I told him I still didn't understand why I have the burning skin pain that feels exactly like my foot, is on my arms, back neck and throat - sometimes even on stomach and buttocks.
The pain i am in is very severe. When pain began in muscles i was given oxycontin and when it moved into my skin it just became unbearable. Even though the pain is constant I have flare ups where even the fentanyl etc doesn't cover it. Obviously i don't take any more for the flare ups. i am just so confused. If it weren't for another website where a dr recommended the skin punch biopsy i wouldn't even have found out what i have so far. i guess i just keep looking. thank you very much for replying and if you happen to hear of sfn being elsewhere when biopsy on ankle shows it is fine please let me know.
The new drug he has given me to try is because the neuro that referred me to him believes that it is somehow triggered by immune system. whenever i have infections and go on meds i have bad reactions and flare ups. However the new neuro did bloodwork and nothing immune wise showed up.


Thanks again!

Some people cannot convert cyanocobalamin from the injections to active methylcobalamin in the body. This is due to a genetic failure to methylate both B12 and folic acid.

The cyano will show up in the blood from the injection, but the tissues cannot use it.

You can try oral B12... use methylcobalamin 5mg daily on an empty stomach for 3 months. If there are improvements, then the B12 was your problem all along, even with the injections.

The genetic flaw is called MTHFR mutation, and can be tested for.

It is pretty common and many people have it.

Also there are two other blood tests... MMA and homocysteine.
These actually show if the B12 is working in the body. If elevated then it is most likely your B12 treatment isn't working for you. Doctors who are not keeping up with B12 treatment follow the old saw of one injection/month...and this does not work for everyone.

You can buy Methylcobalamin inexpensively at iherb.com, swanson's, or Puritan's Pride. Not commonly in stores yet, you may find it at a big health food store, but it will most likely cost more $$ than online.
example:
http://www.puritan.com/vitamin-b-12-...000-mcg-032860
It is important...must be METHYLB12

Also come UTI treatments use drugs that can cause PN.
Macrobid (Macrodantin)
Cipro, Levaquin, Avelox or other fluoroquinolone.

Do you know what antibiotics you took and how many times?

And--
 

--due to B12 deficiency, you could have small-fiber damage in some places, larger fiber damage in others, and some damage to the spinal cord besides (the term is "subacute combined degeneration").

Long-standing deficiency in B12 can result in all these things, and it would be very hard to distinguish symptoms caused by damage to peripheral nerve from those caused by damage to the spinal cord (especially sensory symptoms).

small fiber neuropathy shows only on feet but burning is everywhere
 

Thank you again for all the info. On my previous post I forrgot to add the name of the new drug the dr putt me on...Methotrexate aNd Folic acid. Back to UTI anibiotics used - Macorbid - reaction was hepatatic and Jaundice and while in hospital I had shooting pain in right side of my neck and temporarily lost hearing in right ear, Quinolones - hives and difficulty breathing, IV anibiotiics began because of reactions - gentamycin- balance and hearing loss, mirrrapenem, heartbeat irregularities, a host of others I reacted to that I am seeing an. Allergist for. A big question for me is the ski punch biopsy - is it not the GOLD standard to do three sites?? Then if I was positive on the thigh AND foot they would know it is non-length dependant sfn? Then it would make sense to try immune drugs. Like I've mentioned the burning started aand remains the worst on my upper body. I know I seem to keep going in circles, but after. 15 years I just finally want answers and I feel I am so close now.