Leviticus 13
30 Ref then the priest shall examine the plague; and, behold, if the appearance of it is deeper than the skin, and the hair in it is yellow and thin, then the priest shall pronounce him unclean: it is an itch, it is leprosy of the head or of the beard.
31 If the priest examines the plague of itching, and, behold, its appearance isn't deeper than the skin, and there is no black hair in it, then the priest shall isolate him the person infected with itching seven days.