When I'm under severe stress, my neck and face will start to go totally red as well, I will get these awful red blotches. It's something that just happens and that I have no control over. And it's not as if it's a side-effect of meds, because I also had this when I wasn't yet diagnosed, when I wasn't on any pain meds yet.

This can happen during a car ride that takes too long, during a doctor's visit or check-up, when having tests done at the hospital, ... it's very unpredictable.