Pretty much anything with frankincense nauseates me and makes my sinuses and throat feel like I've been inhaling smoke after a while! The oil itself smells great for the first hour or two, but after that? I get this almost sooty (as in a chimney) sensation in my sinuses and throat. It's a bit scratchy and I feel like I need to cough - not horrible, but pretty uncomfortable. That's the only note I've encountered so far that's given me real trouble!
I also have a sensitivity to spicy scents. I get overwhelmed and nauseated by them pretty easily. I try to stay as close as possible to most pure floral/herbal scents since I know it isn't likely to create a bad reaction. Fortunately, I've had no rashes - yet! *knocks on wood*