Leviticus 13:27

23 But if the spot remains unchanged and does not spread, it is only the scar from the boil, and the priest shall pronounce him clean.

24 When there is a burn on someone’s skin and the raw area of the burn becomes reddish-white or white,

25 the priest must examine it. If the hair in the spot has turned white and the spot appears to be deeper than the skin, it is a disease that has broken out in the burn. The priest must pronounce him unclean; it is a diseased infection.

26 But if the priest examines it and there is no white hair in the spot, and it is not beneath the skin but has faded, the priest shall isolate him for seven days.

27 On the seventh day the priest is to reexamine him, and if it has spread further on the skin, the priest must pronounce him unclean; it is a diseased infection.

28 But if the spot is unchanged and has not spread on the skin but has faded, it is a swelling from the burn, and the priest is to pronounce him clean; for it is only the scar from the burn.

29 If a man or woman has an infection on the head or chin,

30 the priest shall examine the infection, and if it appears to be deeper than the skin and the hair in it is yellow and thin, the priest must pronounce him unclean; it is a scaly outbreak, an infectious disease of the head or chin.

31 But if the priest examines the scaly infection and it does not appear to be deeper than the skin, and there is no black hair in it, the priest shall isolate the infected person for seven days.

Read all of Leviticus 13