Leviticus 13:2-3, 44-46

“When a person has a swelling,  scab,  or spot on the skin of his body, and it may be a serious disease on the skin  of his body, he is to be brought to the priest Aaron or to one of his sons, the priests. The priest will examine the sore  on the skin of his body. If the hair in the sore has turned white and the sore appears to be deeper than the skin of his body, it is in fact a serious skin disease. After the priest examines him, he must pronounce him unclean.

the man is afflicted with a serious skin disease;  he is unclean. The priest must pronounce him unclean; the infection is on his head. “The person who has a case of serious skin disease is to have his clothes torn  and his hair hanging loose, and he must cover his mouth  and cry out, ‘Unclean, unclean! ’ He will remain unclean as long as he has the disease; he is unclean. He must live alone in a place outside the camp.