I would say 6 months after dx with this I went through a period of 6 months where I would be gasping for air and it was make me feel dizzy. I had chest pressure too. I was tested like you said for asthma,allergies,etc nothing was found of why. As the 6 months went on it went from being several days a week to less time and now rarely happens. Nothing changed in terms of meds. Actually I am on more now. Of course it is important to rule out everything. I saw your post on ivig. I have a friend who has PN who does this weekly. They felt some of her problems may have been from auto immune. I think she finds it beneficial cause she has been doing it for so long. I could be wrong though. I know it is not the same as rsd but I wonder if it would help settle the inflammation that I know it causes