What did an Isrealite have to do if they noticed swelling, eruption, or spots on their body?
Leviticus 13:3 (ESV)
3and the priest shall examine the diseased area on the skin of his body. And if the hair in the diseased area has turned white and the disease appears to be deeper than the skin of his body, it is a case of leprous disease. When the priest has examined him, he shall pronounce him unclean.
Any Israelite who presented with any of the symptoms mentioned here had to go to the priest for examination.
3 and the priest shall examine the diseased area on the skin of his body. And if the hair in the diseased area has turned white and the disease appears to be deeper than the skin of his body, it is a case of leprous disease. When the priest has examined him, he shall pronounce him unclean.