With I said before Morgellons is not a disease. When the skin means that those hazardous factors exceed the affordability of the body. It reacts by trying to remove damaged cells and harmful factors. This creates those irritations. Their shape varies but in adulthood appear open and top edges into the interior. The skin is diseased cells restores push outwards. This occurs as crystals or fibers. It depends on the depth at which acted that factor.
There is no universal test. But if doctors did not find anything more than sure you have Morgellons. Skin appearance may differ from case to case. Some may be small as measles. Others may be 15 mm and the oblong or other shape.
Basically skin appearance and lack of any infection in the body lead to one conclusion. You have Morgellon "disease" (reaction).