I think getting a skin biopsy is probably the last thing left to cross off your list.

I went through several months of not being able to see well too - the opthamalogist could find nothing wrong. If you've had a MRI to rule out MS and don't have any obvious motor deficits, doctors don't generally seem to dig deeper to figure this out.

I went to the ENT as well. It was a pretty useless trip for 800 bucks it cost to to have him prescribe vestibular rehab to me for my disequilibrium and give me a wastebasket diagnosis. The ENTs look at the nueros for answers and the neuros look back at the ENTs. It's very frustrating when you find yourself in this place.

Besides having burning all over my body, face, back of neck and head, I have symptoms behind and in my left eye, in my jaw, on the left side of my throat and now (this week) it has moved into the left side of my nasal cavity. At the onset of my symptoms, my experience was the opposite of yours, I was hypersensitive to smells. Even that clean laundry detergent smell you have when you put on freshly washed clothes made me want to throw up.

My new primary says that sometimes these things are not well defined or characterized. And as much as that ticks me off, she is very much correct because there is no way to test for this stuff. It could just be strange symptoms of SFN. However, something caused this. I hope you do find someone who cares enough to find a cause.