Welcome!
I did have the punch biopsy done and was diagnosed with SFN. I understand how it feels to be told it is idiopathic. I've actually come to hate that word. That being said I have come to realize I can't drive myself crazy trying to find out what caused all this.

I've had SFN for 6 years now. In the beginning I went to many different doctors. I even went down to Hopkins. All this with no real answers. Every doctor has a different opinion (guess) and wants to try a different med. I can't take most of the meds so I take a few and try to do my best with what I have.

Don't get me wrong, I still search for answers but once in a while. Not every minute of every day.

I totally agree with you. They are missing something that causes neuropathy. My GP ( who left sadly) told me they are only beginning to locate antibodies that cause this. He said maybe mine was caused by an antibody they don't know about yet.

Could be true!