Delusions of parasitosis (DOP) is a psychiatric disorder in which patients mistakenly believe they have a skin infestation. As Koo and Lee reported in the American Journal of Clinical Dermatology (2001;2[5]:285-290), DOP is actually very rare, and oddly, individuals diagnosed with it have no history of mental illness.

In fact, patients seem cognitively intact in every way while adamant that something inside of them is causing itching and other disturbing sensations (Dermatol Clin. 1996;14[3]:429-438). Some of the earliest patients exhibiting these symptoms expressed belief that their symptoms were due to a parasite. Because a known parasite could not be identified on superficial exam, doctors assumed the patients were delusional. A recent explosion in the diagnosis of DOP raises suspicion that these unfortunate people may actually have had a real, unrecognized disease all along (J Am Acad Dermatol. 2007;56:705-706).

In 2002, Mary Leitao, a Pennsylvania mother, noticed unusual fiber-containing lesions on the body of her 2-year-old son. Unable to find a diagnosis, Ms. Leitao began to call the ailment Morgellons disease (MD) after discovering a similarly named condition resembling her son’s in a 17th-century medical text by Sir Thomas Browne. Since Ms. Leitao started the nonprofit Morgellons Research Foundation in 2003, more than 14,000 families have registered.

I recently completed a descriptive study of 122 patients who had a positive in-office examination for microscopic, subcutaneous fibers. The top 10 symptoms specific to the patients’ skin condition and experienced by more than 70% of the sample were: crawling sensations under the skin; spontaneously appearing, slow-healing lesions; hyperpigmented scars when lesions heal; intense itching; seed-like objects coming out of the lesions; black specks coming out of the lesions; a sensation of something trying to poke through the skin from the inside out; “fuzz balls” on intact skin (balls of fine fuzz that are usually only visible microscopically); fine, threadlike fibers of varying colors in lesions and intact skin; and thick, tough, translucent fibers that are highly resistant to extraction.

When commercial laboratories examine wound biopsies of MD patients, the fibers are usually mislabeled as textile in origin. However, when matched to 100,000 organic and inorganic substances in an FBI database, the fibers were unique and incomparable. Thus far, only individuals claiming to have MD have been observed to have these unknown fibers in their skin. (Research scientist Randy Wymore, PhD, and colleagues presented these findings at the 14th International Molecular Medicine Tri-Conference in San Francisco in 2007.)

The distinguishing characteristic of MD is the presence of microscopic subcutaneous fibers, which can be visualized with lighted magnification. If a person complains of MD-like symptoms, the practitioner should examine the skin thoroughly before initiating a psychiatric referral, because the diagnosis of a delusional disorder should not be made lightly.

The CDC began investigating MD in January 2008, but for now the disease’s cause and cure remain a mystery. Whether or not MD proves to be a distinct entity, its victims deserve to be taken seriously and treated with respect. Primary-care clinicians can make a difference to these patients through validation, reassurance, and a commitment to help.

Dr. Savely is an expert in Morgellons disease as well as Lyme disease and other tick-borne illnesses.