Hello all! I’m just adding my own experiences with this condition to the forum. It started around a year ago with no particular triggers that I can think of (the only diet change I’ve made any time recently is soy milk instead of dairy but this was long before it started happening ) aside from possibly anxiety which I have just started treatment for, although that has been a problem for most of my life.
It happens when I enter a warm place from somewhere colder, such as every single day when I first come inside the office or come home from grocery shopping (I walk and carry the bags which causes me to heat up). It also occurs when I exercise at home. In both cases it tends to last as long as an hour even when I cool myself down.
I get the rash and ‘clear’ hives (but not really the small red spots like some people get) all over my body. As I mentioned anxiety before you can imagine this doesn’t help with that since I worry about people seeing it and passing comment.
My doctor was unsure of what it is (I had a blood test which came back normal), so I’m glad that this forum has helped me pinpoint what I have due to the common experiences you all have had.