Have you researched mast cell disorders? I only mention it because I know it can cause rashes, severe GI symptoms, and dysautonomia. I don't know much about it, what else it can cause, but there is a forum if you wanted to ask questions there. Some people are "leakers" (chronic milder symptoms) and others are "dumpers" (sudden onset of more severe symptoms.) http://mastcelldisorders.wallack.us/yabb/YaBB.p

More importantly, have you considered applying to the NIH Undiagnosed Diseases program? You have so many different things going on, with several positive test results, I think you might make a good candidate.

http://rarediseases.info.nih.gov/Und...eases/FAQ.aspx

Tatia