There are only 2 tests that I've heard of for small fiber PN and not all Drs. are real aware of the one test, the skin-punch biopsy. You have the burning and as you say, symptoms of sfpn. I don't remember the other test, I think it's a sweat test or something like that, maybe someone else will post. Small fiber PN is when the tiny nerves in our skin are damaged.

I had the skin-punch and it's very easy on you to have done and Johns Hopkins will do the checking on your skin samples and results by mail. I can give you the details if you want. Just post me a private message here and I'll look for it. You would have your Dr. get the skin samples, I had 3 and you mail them to Johns Hopkins in Baltimore, MD. Or you may be close to one of the few places that does this test in the US. There may be around 10-12 now.