Stacy,

The gold standard for SFN is the skin biopsy. It is expensive, so make sure beforehand that your insurance will cover it. It takes two weeks for the result.

I had one in 2013 that I was certain would come back abnormal due to my sensory symptoms. Alas, it did come back abnormal, demonstrating decreased nerve fiber density in the skin.

If you suspect SFN, this is the test that I would be seeking if I were you.

I sincerely wish you the best in your journey.

Jason