The so called Morgellon, is no mystery, is just an insect with several shapes and colors, because it undergoes metamorpohosis.
These tiny flying insects infest the insulation fibers in the attics, air condition ducts, carpets, and you can see them in new clothing in department stores, if you pay attention and have good eyesight.
There is a widespread infection of little black flies like pepper specks, that bite, & deposit eggs on tunnels beneath the flesh of living animals & humans. After birth they spin little tubes, made of fibers (sometimes hair, silk or cotton fibers). In the tube, they undergo their metamorphosis. Newly emerged flies are usually pale & glow and bite. They do not acquire their typical colors after certain time. Those insects are the so called Morgellon and is very hard to get rid of them
The reason behind the denial of this infestation, is that most western countries, are in period of austerity and budget constraints , labeling the infested person as mentally ill ( "delusions of parasitosis) is the cheaper answer.