Thematic Bible: Levitical ceremonies prescribed for

"When someone is infected with a boil, but after it's healed, in place of the boil there remains a white swelling or a bright, white-reddish spot, he is to present himself to the priest. When the priest undertakes his examination and finds that it appears more extensive than skin deep and that its hair has turned white, then the priest is to declare him unclean, since an infectious skin disease has flourished in the boil. read more.
If the priest undertakes an examination, but there's no white hair in it and it's not more extensive than skin deep, but it's dull, then the priest is to isolate him for seven days. But if the infection has spread in the skin, then the priest is to declare him unclean. It's a skin rash. If the scab remains in place and doesn't spread, then it's the scab from the boil. The priest is to declare him clean."