Having "strange" triggers is completely understandable, sure. Memory works in odd ways. But what it comes down to is this:
Where do we draw the line? Should I have to warn for every innocuous object mentioned in my fic, just for that one special snowflake who's triggered by lampshades or roast beef? I feel badly for those who have unique, seemingly innocuous triggers, but you can't expect the real world (or the internet, much less) to accommodate the whims of every single person. If you are legitimately freaked out by something as commonplace as hands, I think it's time to either a) lock yourself in a small room for the rest of eternity so you never have to see someone else's hands again or b) go get some professional help ASAP. Just sayin.