Curious: changing triggers over the years?

As I’m exploring the possibility of MCAS (more details below if you want to know), I’m wondering if others have had changing triggers and reactions throughout their lives. For example, I’m in my 40s and recall twice having full body hives as a teenager that had no clear cause. And in my 20s/30s running for exercise would give me itchy legs, and I’d get a hive or two in random spots for no apparent reason. I’ve also always gotten irritated and itchy from vibrations (massager, hot tub jets) which I just read can be MCAS. Currently, I have different symptoms and triggers from these, and I’m curious if MCAS could have been the cause all along and if my body is just finding new and different ways to react (fun!)

Background in brief: I long suspected but recently dx with hEDS. I have issues with dizziness/fatigue/head pressure along with a lot of GI stuff that I’ve been trying for decades to figure out. Looking now at MCAS and dysautonomia. Finding some relief on Pepcid/zyrtec/singulair!