Help for an old burn my son has

Several years ago, while welding, a piece of slag flew into my DS shoe top and down on the top of his instep. He was wearing his work shoes, and don't really know how it managed to get clear down there, I know he had them tied. Anyway, till he got his shoe off, the hot slag burned through his sock (obviously) and he had a really nasty burn. I had him put aloe vera leaf gel on it right away, which did help. I have plants, so just ripped him off a leaf and told him to use it up. It healed up, but looked pretty ugly. Fast forward about 5 years till the present. This old burn is scaly and lots of times itches him terribly. He scratches it, of course and sometimes manages to scratch off pieces of skin. He doesn't feel it, as he said it probably damaged some nerves in the burn, but not in the whole thing. It is not an open sore, not draining or anything like that. He never has had infection in it. What I am wanting to know if there is anything that he can put on it that would help take away the itching? If it would help, I think I could get him to let me take a picture of it so you'd know what he's dealing with. TIA