It's definitely only on his wrist, but we really don't know the specifics of how it's transferred / how long it incubates before its contagious, etc. I'd be remiss if I didn't mention that the friends I watch it with think I'm an idiot and believe there's about a 0% chance that she got greyscale. I just thought it was interesting...
Who knows.
https://scontent-lga1-1.xx.fbcdn.net...a1&oe=55F0A91B