@sillysocks84 Do you mean that ME/CFS is a type of mast cell disorder or vice versa or that they are one and the same? I am very curious about this topic as I developed severe MCAS in April/May of this year and treating it has been the single best thing I have done since getting ill over two years prior to that.
My histamine blood levels were 3x above the normal limit for six months before the MCAS reactions started (and maybe even prior to that) so I suspect I had some kind of mild, smoldering MCAS for many years b/c so many of the symptoms overlap.
In my case I was unknowingly being exposed to toxic mold (plus viral triggers) and I suspect the mold tipped the balance making the MCAS into the severe, active form. So for me, they are 100% related but I know for others they are not so I guess again it is a matter of different sub-sets?