Mast Cell Activation Disorder
I also seem to suffer from MCAS.
I have found that a mast cell inhibitor, such as Ketotifen (available from Canada), is very useful to control my symptoms. I take 1/2 mg every 2 days. It's highly sedating, but if you take it in the early evening you're OK by morning.
Also, I've also found that selective COX-2 inhibitors, such as Celebrex (200mg used as needed), is also useful. Vioxx was really good, but it's no longer on the market.