Hello @amber3212, I have idiopathic small fiber peripheral neuropathy and my neurologist thought it may be hereditary. I think the reality is as much as I would like to know the cause it is just not to be for me. I hope someone can provide an answer for you. I did a little research on causes and did find an interesting article that just adds a little more clarity.

Small-Fiber Polyneuropathy Could be the Answer Some Fibromyalgia Patients are Seeking
-- http://nationalpainreport.com/small-fiber-polyneuropathy-could-be-the-answer-some-fibromyalgia-patients-are-seeking-8835911.html

Does anyone else in your family have small fiber polyneuropathy?

John