These days whenever my face itches when I’m out in public and I can no longer scratch it, it reminds me of the early days of trying to meditate at a Zen center. You’re sitting there with a group of people and it’s absolutely quiet, and you’re trying to meditate, with your legs crossed and your hands in the “cosmic mudra” in your lap, and then something somewhere on your body starts to itch. But you’re not allowed to scratch it, you’re not even supposed to move.
If the itch is on your face you might kinda look around a little bit to see if anyone is looking at you — especially the Zen master with the wooden board. If nobody is looking, you can try to contort your facial muscles in different ways to relieve the itch. One time I tried to curl my lips in a weird way to blow some air up onto my itchy cheek, but in a large, quiet room with a wooden floor, that was surprisingly loud.
So in general, you’re pretty hosed, you just have to sit there and suffer, hoping it will go away, just like when you get an itch on your face when you’re shopping now.