Leprosy has never been common in the United States, although at one time there were a few leper colonies to deal with those who had emigrated. A laboratory in Louisiana used armadillos for research into leprosy for a while, and most cases today are a result of some of the test animals escaping. Consequently, it is hard for most Americans to see leprosy as a serious threat, but in that region, and at that time it was a major health hazard, with no known cure.
To most people today, leprosy is a specific disease, but the Hebrew word used refers to a broad range types of infections including boils, gangrene, the disease we call leprosy, and the flesh eating bacteria that occasionally appears in modern hospitals. The laws given here were for the purpose of differentiating between those which were contagious and those which were not, to protect those who were not infected and prevent the spread of disease.
“And the LORD spake unto Moses and Aaron, saying, When a man shall have in the skin of his flesh a rising, a scab, or bright spot, and it be in the skin of his flesh like the plague of leprosy; then he shall be brought unto Aaron the priest, or unto one of his sons the priests: And the priest shall look on the plague in the skin of the flesh: and when the hair in the plague is turned white, and the plague in sight be deeper than the skin of his flesh, it is a plague of leprosy: and the priest shall look on him, and pronounce him unclean.” (Leviticus 13:1-3)
A swelling, an unexplained scab or a discoloration on one’s skin, and especially if didn’t look quite natural should be examined by a priest to see if it was a problem, just as doctors today recommend having such things today examined to catch cancer early.
If the hair in the area had changed color or the discoloration seemed to go below the surface, it was an infection, and not just an age spot..
“If the bright spot be white in the skin of his flesh, and in sight be not deeper than the skin, and the hair thereof be not turned white; then the priest shall shut up him that hath the plague seven days: And the priest shall look on him the seventh day: and, behold, if the plague in his sight be at a stay, and the plague spread not in the skin; then the priest shall shut him up seven days more: And the priest shall look on him again the seventh day: and, behold, if the plague be somewhat dark, and the plague spread not in the skin, the priest shall pronounce him clean: it is but a scab: and he shall wash his clothes, and be clean.” (Leviticus 13:4-6)
A pale spot that appeared to just be on the surface and had no discoloration of the hairs was to be quarantined for a week for observation. If the spot had not spread he was to remain in isolation for another week. If after two weeks, the area was starting to return to normal color and was not spreading, it was just a scabbed over area that was healing naturally. There was no infection and all the person needed to do was wash his clothes after two weeks of isolation.
“But if the scab spread much abroad in the skin, after that he hath been seen of the priest for his cleansing, he shall be seen of the priest again: And if the priest see that, behold, the scab spreadeth in the skin, then the priest shall pronounce him unclean: it is a leprosy.” (Leviticus 13:7-8)
If the scab seemed to spread after being declared uninfected, the person should return to the priest for reexamination. If the priest determined that it was spreading there was infection present.
“When the plague of leprosy is in a man, then he shall be brought unto the priest; And the priest shall see him: and, behold, if the rising be white in the skin, and it have turned the hair white, and there be quick raw flesh in the rising; It is an old leprosy in the skin of his flesh, and the priest shall pronounce him unclean, and shall not shut him up: for he is unclean.” (Leviticus 13:9-11)
If a person had an open wound with swelling and discolored flesh or the hair was turning white, there was no need to shut him up for observation to see if an infection developed. He obviously had a well developed infection.
“And if a leprosy break out abroad in the skin, and the leprosy cover all the skin of him that hath the plague from his head even to his foot, wheresoever the priest looketh; Then the priest shall consider: and, behold, if the leprosy have covered all his flesh, he shall pronounce him clean that hath the plague: it is all turned white: he is clean.
But when raw flesh appeareth in him, he shall be unclean. And the priest shall see the raw flesh, and pronounce him to be unclean: for the raw flesh is unclean: it is a leprosy.
Or if the raw flesh turn again, and be changed unto white, he shall come unto the priest; And the priest shall see him: and, behold, if the plague be turned into white; then the priest shall pronounce him clean that hath the plague: he is clean.” (Leviticus 13:12-17)
If the infection caused the loss of pigmentation over the whole body but the skin was intact, and the person was healthy, it indicated the infection was no longer spreading and would not infect others. Open flesh wounds indicated the infection was still dangerous. If it healed back up, and showed no more discoloration the person could be considered safe to be around.
“The flesh also, in which, even in the skin thereof, was a boil, and is healed, And in the place of the boil there be a white rising, or a bright spot, white, and somewhat reddish, and it be showed to the priest; And if, when the priest seeth it, behold, it be in sight lower than the skin, and the hair thereof be turned white; the priest shall pronounce him unclean: it is a plague of leprosy broken out of the boil.
But if the priest look on it, and, behold, there be no white hairs therein, and if it be not lower than the skin, but be somewhat dark; then the priest shall shut him up seven days: And if it spread much abroad in the skin, then the priest shall pronounce him unclean: it is a plague. But if the bright spot stay in his place, and spread not, it is a burning boil; and the priest shall pronounce him clean.” (Leviticus 13:18-23)
Blisters and boils were fairly common and usually healed with no major problems. Swelling or discoloration where a boil had been indicated a possible infection and was to be checked by a priest. If the discoloration appeared to go beyond the surface or the hair had lost it’s color an infection was present. If the hair had not changed color or the flesh appeared to be regaining the natural pigmentation, the person was to be observed for a week. If the discoloration spread there was an infection, but if it didn’t, the boil just hadn’t healed yet.
“Or if there be any flesh, in the skin whereof there is a hot burning, and the quick flesh that burneth have a white bright spot, somewhat reddish, or white; Then the priest shall look upon it: and, behold, if the hair in the bright spot be turned white, and it be in sight deeper than the skin; it is a leprosy broken out of the burning: wherefore the priest shall pronounce him unclean: it is the plague of leprosy.
But if the priest look on it, and, behold, there be no white hair in the bright spot, and it be no lower than the other skin, but be somewhat dark; then the priest shall shut him up seven days: And the priest shall look upon him the seventh day: and if it be spread much abroad in the skin, then the priest shall pronounce him unclean: it is the plague of leprosy. And if the bright spot stay in his place, and spread not in the skin, but it be somewhat dark; it is a rising of the burning, and the priest shall pronounce him clean: for it is an inflammation of the burning.” (Leviticus 13:24-28)
Any open wound that seemed excessively hot or was discolored was to be checked by the priest for discolored hair, indicating infection. If the hair had not changed color, or the discoloration looked like a normal wound healing, they were to shut the person up for observation for a week. If the discoloration didn’t spread or appeared to be healing it was just inflammation causing the heat, rather than an infection. Inflammation is a natural response to injury, and does not necessarily indicate infection.
These guidelines provided a practical way of identifying potentially dangerous contagious infections for people who were not trained doctors..