That's very interesting. I have read that allergies can cause a 'chest heaviness' which may be what you are experiencing. Obviously a quick bout of chest inflammation might cause this (an allergic reaction)? I would guess this is part of your allergic reaction, obviously, and I think a fair number of people have it. Doctors just don't know why. But I'm sure it's scary to have chest pain. They've done a full work up to make sure it is nothing coronary related or anything like gerd?