Hi and welcome to the forum! You know, your reaction doesn’t sound allergic at first blush (which is probably why antihistamines don’t help — and likely, a low histamine diet may not help, either). Some non-allergic inflammation will respond to steroids, though. I wonder if your doctor checked your inflammatory markers? CRP? SED rate, etc? Did anyone biopsy your inflammation (which can give answers, but the biopsy itself can increase the inflammation — a lousy situation). Do you have any other symptoms you would link to your infammation? Hang in… It seems that many of us have LOTS of funky inflammation 🙂