A study from the Centers for Disease Control and Prevention (CDC) found no sign of an infectious agent or environmental exposure that could explain the mysterious skin condition Morgellons disease. Patients with the condition report crawling, itching, and stinging sensations, and they often see tiny fibers or filaments that poke out of sores on their dry skin. The CDC study found that these fibers were mostly bits of cotton and nylon, consistent with fibers found in clothing and carpeting. The study was not able to reveal the exact cause of the condition, but roughly half of the people in the study had illnesses, most psychiatric in nature. By ruling out an infectious cause, physicians will have much more information on how to treat patients.
For more information on treating patients with delusions of parasitosis, read the article "Treating Patients With Delusions of Parasitosis: A Blueprint for Clinicians."