Cat taking its own fur off, any advise?

Felix or flix as he's known, scratches under his chin, the scent glands on the top of his head and behind his ears. He does it to the point where they bleed and when they scab over he scratches again. Its my mum's cat and they've taken his color off because it seems to irritate him. He stopped scratching but as he goes out side, she's worried that now he has no tag or light reflectors (he's a black cat btw) He is chipped but not everyone checks for that. He's eating great, pooping fine. drinking great. Doing everything normal. Any advise on how to keep this kitty safe outside with out a color as he takes his fur off when he wears it. It would be cruel to keep him in. He only ever wore it go outside. Help.