Hi. Is it just that round area? The pic is blurry so I can’t see well. If you look closely, is there any sign of any problem with his scales there? Maybe a wound, scar or something else? I ask only because of the round shape, which I’ve found has occurred on one of mine who has had small growths (papilloma and similar). Usually we just leave shed remnants alone and they should come off on their own or with the next shed. If they don’t come off with the next shed, you may need to intervene to avoid build up.