Weird habits

So when my niece was a baby she'd rub ears to fall asleep, my nephew played with hair and my son rubs elbows. Well he used to rub them. He's now been scratching and digging at them to the point of my elbows have scabs and are bleeding 😭🤦‍♀️ I'm not sure what to do about it, if I put the blanket over them or pull them away he will scream like a hurt cry!! Is anyone going threw this? And it's not a phase, he's been doing this almost his whole life he's just getting aggressive now.