Why when the leprosy covers the entire body the leper is pronounced pure?
The Test for Leprosy--Leviticus 13:1-46
It can be seen that leprosy might begin with an eruption, a scab, a blotch, a boil, or a scar in one’s flesh from fire. When God gave the Mosaic Law to Israel it provided the priest with information enabling them to diagnose leprosy and to distinguish it from other less serious skin deceases.
Leviticus 13:1-2 NASB
1 "Then the Lord spoke to Moses and to Aaron, saying, 2 “When a man has
on the skin of his [a]body a swelling or a scab or a bright spot, and
it becomes [b]an infection of leprosy on the skin of his body, then he
shall be brought to Aaron the priest or to one of his sons the
priests."
It was accepted that leprosy could reach a stage in which it was no longer infectious, this happened when the diseased action spread all over the body, turning it white. Provided that no raw flesh appeared on him. This was evidence that the spread of the infection was over, and it posed no further danger to anyone. Leviticus 13:12-17
Leviticus 13:12-17 (NASB)
12 If the leprosy breaks out farther on the skin, and the leprosy
covers all the skin of him who has the infection from his head even to
his feet, [a]as far as the priest can see, 13 then the priest shall
look, and behold, if the leprosy has covered all his [b]body, he shall
pronounce clean him who has the infection; it has all turned white and
he is clean. 14 But whenever raw flesh appears on him, he shall be
unclean. 15 The priest shall look at the raw flesh, and he shall
pronounce him unclean; the raw flesh is unclean, it is leprosy. 16 Or
if the raw flesh turns again and is changed to white, then he shall
come to the priest, 17 and the priest shall look at him, and behold,
if the infection has turned to white, then the priest shall pronounce
clean him who has the infection; he is clean.
Is vitiligo leprosy? (from Google)
These two conditions are entirely different from each other. Leprosy is an infection caused by a bacteria in which the patient develops light-colored patches with loss of sensation and loss of hair over these patches. Vitiligo, on the other hand, occurs because of the loss of melanin pigment from the skin.