Yes, if there weren't any sweat glands and hair follicles in the sample they probably couldn’t check their innervations.
When the small fibers that innervates these structures are affected there is a reduction in the regulation of these structures (by neurotransmitters such as Acetylcholine, Norepinephrine) they don’t get the commands to sweat, dilate and constrict the blood vessels etc., so the damage isn’t caused by reduced blood flow .
Although I guess it might happen indirectly, since the small fibers innervates the blood vessels then there might be also a problem with blood supply to the area.

This all makes sense, thank you. I guess I have to pay attention to other possible signs of autonomic issues. That was my concern along with circulation. My late husband had type 1 diabetes since age 7 and had diabetic neuropathy as well as CICP so seeing all that isn't helping me right now. I appreciate your help though...it means a lot. I am still curious about what triggered all this as I am sure many of us are.

summerfun - just wanted to pipe in and say that when I had my skin biopsy they did an epidermal nerve fiber density (ENFD) and sweat gland nerve fiber density (SGNFD) count. Sounds like they may have done something similar for you - mine also showed significant reduction of nerve fibers in the sweat glands which would suggest autonomic and/or SFN.

Thanks for letting me know. I have left a message for my doctor so when he gets back to me I will let everyone know.