Father and Daughter - Same Picking

Hi! I think my husband has a CSP - he scratches his own fingers around the nails and his ear. He used to bleed in the past, now he just has huge hard ugly bumps on both his hands and one of his ears. He has been doing it since early childhood and still can't stop doing it. No one ever told him to check it or took him to the doctor. Our 2-year old daughter has been playing with her fingers almost from birth, too. Hers is a little different – she likes to grab someone’s pinky (and only a pinky!) and sort of massage it softly with her fingers. If she doesn’t have someone’s pinky, she will massage her own thumb and index finger in a constant motion. She does it all the time, watching tv, riding in a car, but especially when falling asleep. And she even does it in her sleep – I observed it many many times! Can that be a disorder if she has it at this tiny age? It this hereditary? I've also heard somewhere that it could be some kind of skin disease? Help! I don't want my little girl to have ugly bumps on her hands and it is also very disturbing to watch her fingers be in constant motion.