Do you have nickel allergies? Not a lot of platinum watches I can think of, Cartier has CPCP collection platinum tank watches (tank a vis, tank americaine, louis cartier), Rolex makes a cellini in platinum, Jaeger Le Coultre makes a remarkably expensive one too. All these watches start at maybe 9 or 10 thousand dollars. I don't know about titanium, I'm only aware of large gents sport models. If you do find a nice watch that you like try painting the back of it with some clear nail polish, and wear it loose so it doesnt stick to your skin.