Thanks, kiwi. My fingers are crossed. I've gone on a low histamine diet, and I believe that has pulled me out of a major flare I was in. Now that I've learned more about histamine, I recognize that I was on a high histamine diet on a daily basis. And in retrospect, I can look back and see that my absolute worst flares were also due to histamine-laden meals.

I don't know if a Histamine Intolerant dx can be made without an MCAS dx, but I quite by accident stumbled upon an immunologist who is well-versed and believes in both.