It is a leprosy — It is a sign that such baldness came not from age, or any accident, but from the leprosy.
Related Commentaries of Leviticus 13:42
Leviticus 13:42
42 And if there be in the bald head, or bald forehead, a white reddish sore; it is a leprosy sprung up in his bald head, or his bald forehead.