Defilement: Caused by Leprosy

The priest is to examine the infection on his skin, and if the hair in the infection has turned white and the sore appears to be deeper than the skin, it is a skin disease. After the priest examines him, he must pronounce him unclean.

…the man is diseased; he is unclean. The priest must pronounce him unclean because of the infection on his head. …

Then the LORD said to Moses,

If a descendant of Aaron has a skin disease or a discharge, he may not eat the sacred offerings until he is clean. Whoever touches anything defiled by a corpse or by a man who has an emission of semen, …