Spider mites are tiny, and have an unusual (in developed countries, that is) way to go through the four stages of an insect life cycle:
The adult spider mite lays eggs inside the nose of a warm blooded mammal, and then the eggs get into the digestive tract, and go through two more phases, two more stages of the cycle. They come out hungry nymphs that are ready to molt into fully developed spider mites, just need a little help from the host: skin juices.
If this makes your stomach turn: yeah, it turns my stomach too. And makes me feel violated, abused, and all the horrid feelings we so try to avoid, and here it is.
Because of this unusual habit, doctors, it seems haven't discovered that a large segment of the population is host and nursery for these parasitic creatures.
My guess is, supported by my own muscle testing, is the Morgellons, the condition that drives people crazy and to suicide, is simply (sounds ridiculous, but it is in fact more simple that the descriptions other give to Morgellons) spider mite infestation.