I have a similar issue, though I suffered no diagnosis instead of a misdiagnosis. One doctor did try to prescribe me steroid cream. I know what you mean about the boils deep in the skin, I get a minor case of those.

Thanks for the information. I don't see any new leads for me here, but if you have any, please share. I'm on a strict diet of beef, fish, and that's it. (Other non-shellfish meats are OK too.) There are very few things I can eat. Sometimes I cheat with things I'm slightly allergic or intolerant to. I have to be very strictly gluten-free.

I'm undergoing ongoing testing with professional help to try to find causes.