Anytime the pharmaceutical cartel says cause unknown, it means they couldn't think of a pretend reason good enough to be convincing to explain the parasite symptoms. Your body's not so stupid it attacks itself.
It's attacking the parasites in those locations. The parasites gnawing away, the infections they carry spreading locally and your body sending in white blood cells to kill both all combine to cause a lot of 'mysterious' pain and inflammation.
But they are ready with drugs aplenty to manage those symptoms, right?
Try a good internal cleanse WITH a zapper for a couple weeks, and in case your did have an infection, which is now dumped into you, get Dr. Clark's book, section 'pain from head to toe', and look up your symptoms for what infection and treat accordingly. I've outlined that which I use, in my post here: