According to the Web site of the Morgellons Research Foundation,<www.morgellons.org>, most individuals who have morgellons disease report crawling, stinging, and biting sensations; nonhealing skin lesions; and fibers associated with those lesions. The fibers are the most striking feature of the malady. They are generally described by patients as white, but clinicians also report seeing blue, green, red, and black fibers that fluoresce when viewed under ultraviolent light.

Nearly all people with the illness report extreme difficulty with concentration and short-term memory. More than half experience mood disorders. Parents of children with the illness report that their children often have comorbid psychiatric illnesses such as mood disorders, attention-deficit/hyperactivity disorder, obsessive-compulsive disorder, or autism spectrum disorder.