Leviticus 13:11-15

it is a chronic leprosy on the skin of his body, and the priest shall pronounce him unclean; he shall not isolate him, for he is unclean.

If the leprosy breaks out farther on the skin, and the leprosy covers all the skin of the person who has the infection from his head even to his feet, as far as the priest can see,

then the priest shall look, and behold, if the leprosy has covered his entire body, he shall pronounce the one who has the infection clean; it has all turned white and he is clean.

But whenever raw flesh appears on him, he shall be unclean.

The priest shall look at the raw flesh, and he shall pronounce him unclean; the raw flesh is unclean, it is leprosy.