Heather, I giggled when I read your reply. Once (I think in Amsterdam's airport), I had a breast exam (it was much, much more than a pat down) that was more extensive than any clinical GYN exam of those body parts.... E V E R !! All I could figure is that I was wearing a funky sports bra that made me look like a uni-boob...(which hopefully they did not think was a uni-bomb) and I had taken a long scarf off prior to going thru the machine. Fellow travelers, not to worry, we are Global Entry, but realize that does not mean diddly-squat in other countries.
Many decades ago, I was running very late for a flight (business trip and traffic in whatever large city was awful), and they kept scanning me....I finally realized it was the hooks on my bra......I told them I "had" to make that flight, and I would leave my bra with them, if I needed to..........I think I took my suit jacket off, lifted my shirt in the back and got the all-clear quickly. I did make the flight. One time it was a wrapper on a roll of mints in my pocket.....again decades ago when they would set the machines to very sensitive if there was something strange going on in the world or that destination.
Deborah, my first guess would have been lotion re: the wrist issue....or maybe something (chemical like) rubbed off from your carry on bag, etc.