I took the permethrin and ivermectin tablets a few times, maybe five times, over the course of two years. It would always look like it worked but would come back in a few days or week. Doctors believe scabies is easy to cure. That doesn't mean I don't have a parasite, but that is what they conclude. None, and I've seen many, will do another punch biopsy. Since the CDC investigated morgellons and believe it to be a psychological illness, the doctors go for that diagnosis despite evidence to the contrary.