Poor thing! Looks like a case of leg mites to me ... based on other pictures I've seen on this website. I think it's time to slather on the Vaseline. I've read on other posts on the subject that olive oil or vegetable oil also works. If it were me, I think I would probably keep him/her separate until his/her legs clear up, since I don't know if leg mites are contagious, but rather suspect they are.
Good luck!