DOA - Diamine Oxidase and Degrading Histamine

I had some genetic testing done because I have a Mast Cell Disease (Systemic Mastocytosis) that gives me SEVERE "allergic" reactions to just about everything. But get this...I'm NOT ACTUALLY allergic to all this stuff. I've been tested for just about everything under the sun. I'm ACTUALLY allergic to a couple of things but not many.

I've been living on a low histamine diet because my Immunologist and I noticed I was reacting to LOADS of high histamine containing foods. Now, one day I can eat spinach and be fine; and another day I eat spinach and I need an epi pen and medical intervention. What gives??

So, I've learned that on a SPECIFIC GENE, on a SPECIFIC allele you can tell whether you are one of those people who have this marker for low DAO (diamine oxidase) one of the enzymes responsible for degrading histamine. So I went to my test results and had a look...guess what? I am.

So is THIS why I REALLY having "allergic reactions" to foods??? And does it have NOTHING to do with my Mast Cells having a dumping party in my blood stream? Or is it both?

And what do I do about it?