The parent may have misdiagnosed their child here. This could be Transient Tic Disorder. It's super common. Kids get random physical/vocal tics, including licki

The parent may have misdiagnosed their child here. This could be Transient Tic Disorder. It's super common. Kids get random physical/vocal tics, including licking fingers/hands. Usually they just go away with time. Not much you can do and definitely stressing out your child won't help. There's no "reason" for them. As for why the child said it was because his hands were dry: I hate to say it but maybe the poor kid just wanted to stop their maybe-a-bit-intense parent from "grilling" them about it again.