Sorry, my brain isn’t working but what is SFN?
Maybe this helps
I don't have the first idea what that means.
I had all the symptoms of SFN, and had a skin biopsy performed by Neurologist. He was certain I had it. The test came back negative. He was surprised. He told me the difference is, if you have SFN, you have a neurologist for a dr. and if it is not SFN, they would send you to a rheumatologist. I have not seen a rheumy since then, since I have been tired of seeing dr's, to be told its just fibro. I still have burning sensations in my feet and legs. And also have arm and leg numbness. hope that helps.