Burning Arms and Legs (Acid Under Skin)
 

Hi all,

I experience flare ups triggered by exertion, stress or lack of sleep.

Flare ups consist of ~3 days of burning arms and legs or what can be described as an excruciating 'acid under the skin' feeling. This is followed by 2 days of very tender muscles in my arms and legs presumably as a result of the nerves being irritated or irritating my muscles. I also experience varying degrees of fatigue during my flare ups.

I have no numbness or discoloration or swelling etc... Only other remarkable thing I've noticed
is that recently when I'm in the acute 'burning' phase I get lightheaded when I stand up and my legs will shake or spasm on standing.

When I'm not flared up I have no symptoms. Is that strange?

I've had these flare up for the last 6 years and I guess I'd just like to find one other person in the world that experiences the same thing. Just one damn person lol. Does anyone have any insights or experience similar flare ups?

The best I've come up with is that this is a small fiber sensory neuropathy but I'll have to confirm with my next neuro.

Thx

Could be HNPP...
http://www.hnpp.org/hnpp_symptoms.htm

Went to see a new neuro today. He did a good workup including NCS, he basically said that my nerves are fine but he theorized that my small fiber neurons are just hyper excitable. He didn't think that a skin biopsy would uncover any pathology.

Showed him that my TSH had recently tested high and he didn't completely rule that out as an underlying trigger.

Unfortunately he didn't have any compound creams that he prescribes for burning.

Unfortunately, the ONLY test to uncover answers about the small fibers IS the skin biopsy. The NCS (and EMG) is unable to detect issues within the small fibers.

It's too bad he won't pursue this for you so you may confirm/deny SFN.

Salut en bloc, he told me that here in Canada there aren't many places that do skin biopsies.

When I was in University about 15 years ago I would suffer from bouts of respiratory alkalosis due to anxiety. I'd feel really dehydrated and had to lie in bed for a day or two till my ph balanced itself.

Although I rarely get noticeably alkaline anymore, this is still interesting because I was just reading about how alkalosis triggers neuronal excitability which is what this neuro thinks I have.

I also read that caffeine has an excitatory effect on the nerves and makes them more apt to reach their firing threshold. I'll experiment by going without coffee next time I have a flare up and see if it helps at all.

Does anyone know what sensation/s is/are associated with nerves firing?

I'm in a tough spot because exercise is one of the things that triggers my flare ups (consisting of generalized fatigue and nerve inflammation lasting a few days post-exertion).

So I've tried to avoid exercise for the last 6 years but now my cholesterol is getting quite high and I've gained weight as well.

According to this article exercise should reduce inflammation of the nerves including inflammatory cytokines etc... I wish I understood why it seems to have the opposite effect with me.

I'm still thinking that the underlying cause for my flare ups is metabolic like a ph issue or possibly hypoglycemic episodes, lactic acidosis or something like this.

I'm sure that if I spent a week in the hospital while they ran tests and had me run on treadmill to induce a flare up and they measured all the changes in my body that they would find the underlying cause. It's really frustrating that because my illness is so unconventional that the will of the doctors to get to the bottom of it or to invest such resources as having me admitted for a week is sorely lacking. I'm in Canada so it's not like I can just pay to have them do what I want.

I'm guess I'm just going to try to do these tests on my own, like I can buy a blood sugar monitor for ex.

We have the same thing here in the US. All the doctors do there own separate piece of the puzzle. No one wants to take the time to investigate every avenue to get the complete puzzle.

I have searched for a diagnostician in PA and there does not seem to be one. I tried to go to the undiagnosed diseases section at Hopkins but they wouldn't take me because they said I have the diagnosis of SFN. They told my neurologist if any other symptoms show up try applying again.

It really is a shame your doctor won't send you for a small nerve biopsy. It is not hard to have done. Maybe you should try searching for a neurologist who does them.

Ya that's very true.

Like the underlying cause of my flare ups could be in any number of disciplines. It's kind of crazy that I as the patient have to figure out which of these disciplines my underlying cause falls into because as you pointed out, their knowledge is so compartmentalized. I like the idea of a diagnostician and wish that they were more common, if such a thing exists.

Did you get small nerve biopsy and may I ask if the results were useful to you?

Yes I did get the biopsy. It is not hard do. I actually had no pain. It is a punch hole, then they analyze the nerves in the skin.

I think the results were very useful to me. It gave me an answer for my symptoms.

I could understand if your doctor says it's difficult to get done in Canada, but I don't understand his first reason...that no pathology would be uncovered. How does he know this? And actually, ruling out a problem is just as useful. So if the biopsy is negative, it at least rules out SFN. But it could be positive...he can't tell the condition of your small fiber nerves by an exam.

Not only may it give you answers, but those answers may also provide different treatment options.

I would do as Hopeful suggests and get another opinion if that is possible. Or research to see what & where skin biopsies can be done in Canada.

I had two...very helpful. And they can be repeated to gauge progression or improvement.

I understand your frustration. As mentioned before, doctors are specialized in their respective disciplines so getting a full picture of what is causing/triggering your flare ups is very difficult. You see a neurologist for the nerve pain, a rheumatologist for possible underlying auto immune issues, an endocrinologist or GP for thyroid/diabetic issues, naturopathic if you seek that route and a psychiatrist for when all the above begins to drive you INSANE! They do not ever meet or speak to each other so making any connection between all the internal systems is complicated.

The flare ups you experience have been described by others, although most seem to have some intermediary symptoms like numbness. For me the nerves firing varies, but this past week has been a constant state of pain alternating between "burning feet" and shooting pain. My "normal" is numbness and achey pain in the feet and sometimes hands. Now it has suddenly moved throughout my body . This is not meant to scare you-but you did ask if anyone has experienced anything similar. This neuropathy manifests itself differently in everyone.

As hopeful said, getting the nerve biopsy can be helpful and is not very painful. You read horror stories about them if you google enough, but it is a punch hole usually done in three places going up the leg. It leaves a very small scar and is only unpleasant for the 5 seconds it takes to "punch" the skin for the specimen. I rec'd a diagnosis of small fiber nerve damage caused by innervation of the sweat glands. In and of itself, it does not provide a cause of anything other than confirming what the EKG and nerve conductions studies did not-that there is indeed nerve damage.

It is beneficial to have the biopsy so you know whether or not it is indeed SFN. Other studies can miss this damage completely. On the other hand, it does not mean you will discover the underlying cause. My local doctor did not perform the biopsy. I traveled to Johns Hopkins in Baltimore, Maryland. If you can afford the expenses, and you cannot find a local specialist, it might be worth your while to look into a specialty clinic like John Hopkins. The other positive is that the specialty clinics have teams of doctors from varying specialties who all confer on a diagnosis.

Tyvm cat and en bloc for your thoughtful replies. I really appreciate it.

Given that fatigue is a main part of my flare ups I had considered CFS/ME and dismissed that idea as it didn't seem to fit my case. However, after reviewing the Canadian Consensus on CFS, which spells out in great detail what that condition involves, I feel that my condition can fall within that criteria. What particularly struck me was the post-exertional malaise aspect which can come with a delay of 1 or 2 days after exertion like in my case.

Tbh though, I'm still not completely sure whether to view my post-exertional nerve pain and myalgia as the main symptom and that the fatigue is a byproduct of that, or if I have CFS that happens to be accompanied with nerve pain and myagias.

I guess it would help me to know if you guys ever experience debilitating fatigue when your nerve pain is bad?

I've read about how what I experience could be due to the inappropriate opening of acid sensing ion channels. It makes me think that what my neuro said about my nerves being hyper-exitable, while simplistic, may be true.

Regarding the skin biopsy, I have found a place here in Canada that would do that procedure. It's actually the same place where I had my needle muscle biopsy. I'll keep in mind what you all have said about giving it a try.

However, given that my nerve pain is not constant and it's symmetrical in it's manifestation I'm reluctant to think that there is any underlying pathology that can be found. At least not with the tools that exist today. I suspect that what I have is beyond the scope of science atm and that my best bet is to keep experimenting with what supplements/drugs work best for me and just manage my symptoms the best I can.

Nebulous,

I would be willing to bet that you do have small fiber neuropathy. My symptoms waxed then completely waned repeatedly. 2 years ago I had a biopsy that revealed SFN. Now my symtoms have worsened and it seems as they won't wane completely this time. I hope I am wrong.

I was initially hesitant to get a skin biopsy since it would not reveal the underlying cause which all neuropathies have. I would also have to travel to another city. However, after further thought I believe that knowing what kind of nerve damage is occurring might be diagnostically useful in helping to identity that underlying cause.

Btw, my latest thoughts regarding my condition are that it is some kind of non-demyelinating inflammatory neuropathy possibly with an auto-immune condition as the underlying cause/trigger. I haven't tested positive for any auto-immune markers yet but I'm looking into other ones.

So I will be requesting a referral at my next doctor's visit for a skin biopsy and consultation at the neuromuscular clinic.

Thx again for your input guys.

Good Morning Nebulous :)
 

Was just reading through posts and found yours....so glad to hear you are going to have a skin biopsy. It's very frustrating to have to be your own health advocate but that's the way it is most of the time. I've had to figure it out by myself all the way.

I asked for a skin biopsy in Sept of 2013 and the results floored me. I didn't even know about SFN until I happened upon it on the net. I had already had the nerve conduction, back x-rays, MRI's and the blood work. I had just finished chemo and my A1C was up but I just kept getting passed over by the doctors.

Anyway......my results were 0 on a scale of 0 to 15 with Bako Labs. I have no A or C fibers left in my feet.

It was a huge relief to finally have a dx.

Please keep us posted.

Debi in Georgia

Nice to read your post. Yes I'm also glad and looking forward to see what the results will show.

Congrats on getting a dx. No fibers in your feet, wow. Are you able to feel pain? I also wouldn't have thought it possible to move a limb without any c fibers.

Pain ? Yes and Plenty of it !
 

From what my doctors say and what I've read about SFN you either have absolutely no feeling at all which presents its own set of problems or you are like me and the pain is because the nerves still fire off messages that get all mixed up in the spine and the brain misreads as pain. I can bump my foot and not feel anything but the next time I bump the same area they are pulling me out of the ceiling. It started in my feet and has since moved to my hands and my upper right arm. I have burning, stabbing, electrical shocks and so on.

I'm up now because of the pain. Waiting for my pain pill to kick in for some relief. I am unable to work and had to go on disability and am in my house 99% of the time. For a very active mom and grandmother that was a very hard pill to swallow and still is. I have a wonderful family and they make it much easier for me than some people have it.

Gotta go....my right hand is numb to the point of hurting.

Take care of yourself.

Debi from Georgia

I have never had any tests; but have very similar issues with the feet misfiring. Like they don't know when to stop. As you say; sometimes just slightly stub a toe or foot and the pain is almost unbearable. So much of the pain radiates to the spine. Like you; home most of the time.

Unfortunately I seem to feel I deserve treats; i.e., candy, cookies, etc. Not the best way to treat pain. While watching t.v. late at night, my night time snack is munching on dry Cheerios (Regular, mixed with a majority of MultiGrain Cheerios). I guess it keeps my mind off some of the pain/burning or at least I try to convince myself it does.


Gerry

There are tests that help identify small fiber neuropathy, such as a sweat test (identify if there are areas you are not sweating), sensitivity to vibration, heat, & cold. They can test such things at a specialized facility such as Mayo, I know there are others. They told me they don't generally do biopsies anymore because they can get as much info from these other procedures, which I suppose have less risk to the patient. They have designed and built their own devices to perform these tests, at least it appears so.
Ron

The gold standard test--
 

--for small fiber neuropathy is still, as of this writing, a skin biopsy to enumerate the density and condition of the small unmyelinated fibers in "hairy" skin (the type with hair and sebaceous glands).

There are some other avenues of research that are hoping to be able to do this without taking out a chunk of skin--some microelectric conductivity tests patterned after quantitative sensory testing (another, older technology for attempting to determine small fiber function) among them--but those seem to still be some years away from being determined valid and/or reliable.

Just wanted to chime in. You can have small fiber neuropathy, and have normal tests for the above. I feel vibration fine, heat and cold fine, etc, and my sweat test came back totally normal.

I do, however, have the small fiber neuropathy symptoms (non length dependent, burning, shooting, numbness, pressure pain-they all wax and wane), and my two punch biopsies came back with significantly low nerve fiber density, and I was finally able to get diagnosed. So I think the biopsy is really the only sure fire way to know.

Apparently Dr. Peter J. Dyck and his neurology dept. at Mayo Clinic (Rochester MN) do not believe that a skin biopsy is required. As I said before, at least in 2007, they used devices, combined with software, that quantitatively measured sensitivity to vibration, heat, & cold. The doctors told me that they get enough info from this that a biopsy is often not necessary (and they did not biopsy me). Perhaps these devices are proprietary and that is the reason you are unfamiliar with them.

The device that measures heat & cold sensitivity has a piece that attaches to a part of the body, the foot for example, I believe with a metal contact surface. Then a fluid passes through it at a controlled temperature, causing the temperature to rise or fall briefly. The patient is asked whether they felt the change and the answer is recorded. By using different settings, the patient's threshold is discovered, and this is compared to that of a 'normal' population without neuropathy. If your threshold is above the vast majority of the normal population, this supports a diagnosis of probable sensory neuropathy. The result of this test is considered with other results to make the diagnosis.

Dr. Dyck has been studying neuropathy for about 60 years and did some of the pioneering work in this field. Here is his bio at Mayo:
http://www.mayo.edu/research/faculty...d/bio-00025843
Ron

What you are describing--
 

--sounds very much like qualitative (sometimes also called quantitative) sensory testing; perhaps they have some technology over there that has tweaked it a little, but it doesn't sound like anything new.

Take a look at:

http://www.medoc-web.com/about-us/technology/technique

(though this is by a device manufacturer for doing the test, the description of the process is succinct)

http://www.ncbi.nlm.nih.gov/pubmed/12795516

http://www.aetna.com/cpb/medical/data/300_399/0357.html

(I include this one as it shows that at least some insurance companies don't think the reliability/validity of the procedure is all that good--more on that below.)

http://www.neurology.org/content/60/6/898.full


https://www.aanem.org/getmedia/2621c...iques.pdf.aspx

(This last one mentions Dyck's system and also Von Frey Hairs, which almost no neurologist even knows about anymore.)


I had such testing done when I was in the midst of my acute neuropathy phase; my results were within normal limits though the skin biopsy had indicated some rather abnormal results. Many of the reviewers have noted the necessity of skilled interpretation of testing results and the rather subjective nature of patient responses to the stimuli in doing these tests.