The last pic almost looks like "fuzz" or cotton? If that's so, it might be fungus. How is your husbandry? Keeping the cage clean? What is the humidity like? Is the substrate dry? If its fungus, I've never dealt with it on a snake before, so a vet visit is probably called for. I do know that in a lot of cases, the fungus treatment for humans is the same whether its for athlete's foot, jock itch or even toenail fungus, but I don't know if that would be safe for a snake. If it looks like cotton growing on the snake take it to a vet.
Steve