Very good questions and I wish I had an answer. One question I have is how I can stop this from happening again. There are many books on autoimmune diets and cooking, but not specific for PMR. they seem to think the nightshade vegetables are no problem, so you need to read this recipes carefully to catch this. Also, keep away from salt and sugar is not a bad start.
There seems to be very little research into PMR, at least in America. I know it is a really bad problem in the UK and I am relying more and more on the National Health Service web site for help. When it's powered up I will search my kindle for the titles of the autoimmune recipe books I have and get back to you.