Wonder if you still do have a "smoldering" Lyme process going on. Or, possibly, a low level Lyme-associated infection that has hung around all this time (many who have Lyme, or are thought to, have co-infectioons of other tick-borne pathogens).

I'm not as expert on this as a number of other people who hang around some other areas of this board--but it might not be a bad idea to have a little discussion with wasabi or one of the other denizens at our subforum for that.

THE greater mimicker than PN and other auto-immune diseases? Think about it, as it is not exclusive and possibly concurrent to many possible immune issues.
I know of many in our own area who suffer from Lymes'. Those diagnosed DID have those delightful 'spots' etc that are ideally symptomatic and those diagnosed and treated have been mostly very fortunate. Others, tho, go thru the whole run-around of diagnoses and still aren't getting anywhere.
This is not meant as an insult to those with Lymes'? But, when my tests came out the way they did? I was grateful!
IN all? I have to say that you have the most impressive menu of issues? I am surprised that you have not yet found THE CURIOUS DOC! I truly hope you do soon, VERY SOON! That your son is now having similar sets of issues probably isn't 'fun' either. [Understatement?]
All I can do from here, is to hope and more that you are able to find docs who can actually put the puzzle pieces together! I know how hard it is to try and figure out it all by yourself.
Onward and all that? 's - j