Leviticus 13:2-3, 44-46

“If anyone has a swelling or a rash or discolored skin that might develop into a serious skin disease, that person must be brought to Aaron the priest or to one of his sons. The priest will examine the affected area of the skin. If the hair in the affected area has turned white and the problem appears to be more than skin-deep, it is a serious skin disease, and the priest who examines it must pronounce the person ceremonially unclean.

the man is indeed infected with a skin disease and is unclean. The priest must pronounce him ceremonially unclean because of the sore on his head. “Those who suffer from a serious skin disease must tear their clothing and leave their hair uncombed. They must cover their mouth and call out, ‘Unclean! Unclean!’ As long as the serious disease lasts, they will be ceremonially unclean. They must live in isolation in their place outside the camp.