Tzaraat--"biblical leprosy".

Tzaraat refers to a group of skin diseases that, according to the Old Testament, renders one ritually unclean. Analysis of the text reveals that there are four categories of lesions discussed. Each category has a primary lesion as well as specific secondary changes. The primary lesions include depigmented lesions on previously healthy skin, lesions on previously abnormal skin, lesions on areas of diffuse alopecia, and lesions of localized alopecia. It is unlikely that these diseases have a modern-day counterpart.