This might be a silly question, but is the mast cell stuff related to other allergy stuff? It says on the site that you linked that asthma is also related to mast cells dysfunction. Would nasal allergies be too? I see sinus/lung infections listed on some of the most extensive lists of co-occuring problems with EDS, and I have asthma and bad allergies with lots and lots of respiratory infections in addition to everything else. When I saw that on the lists I wondered what the connection was.
As a side note, I’m amused that emotional upset, exertion, and stress are on the list of potential triggers on the mastocytosis page. So all those years I was right–I really am allergic to final exams, gym class, and unrequited love. ;-P