Leviticus 13:39

36 the priest is to examine them, and if he finds that the sore has spread in the skin, he does not need to look for yellow hair; they are unclean. 37 If, however, the sore is unchanged so far as the priest can see, and if black hair has grown in it, the affected person is healed. They are clean, and the priest shall pronounce them clean.

38 “When a man or woman has white spots on the skin, 39 the priest is to examine them, and if the spots are dull white, it is a harmless rash that has broken out on the skin; they are clean.

40 “A man who has lost his hair and is bald is clean. 41 If he has lost his hair from the front of his scalp and has a bald forehead, he is clean. 42 But if he has a reddish-white sore on his bald head or forehead, it is a defiling disease breaking out on his head or forehead.