This jumps out to me as significant; possibly environmental or an allergen.
Anything else in common with this previous episode, e.g. were you doing the same thing just beforehand, visiting same location, any other kind of exposure?

What do you do for a living/recreation near the times this occurred?

I just googled: peripheral neuropathy rash and found a lot of possibilities.
Here is one list from a symptom checker, which I'd take witha grain of salt at first glance. A lot can likely be eliminated quickly, and anything left may have already been eliminated by your doctors, but you might keep checking other sites for clues to discuss with your docs...
http://symptoms.rightdiagnosis.com/c...y/rash-all.htm

Doc