Last year, the U.S. Centers for Disease Control and Prevention (CDC) launched a study of a curious and controversial condition known as Morgellons disease, which is characterized by creeping, crawling and stinging sensations under the skin.

The project, whose goal is to identify possible risk factors and causes, was prompted by pressure from afflicted people, along with the advocacy groups and Congressmen that represent them, according to CDC spokesperson Lola Russell. Many in the medical community question whether Morgellons is an infectious disease or a psychiatric disorder.

Morgellons has drawn increasing attention since 2002, when a Pittsburgh woman named Mary Leitao launched a Web site describing skin sores and filamentlike structures emerging from her two-year-old son's s skin. After being inundated with e-mails from people complaining of similar symptoms, Leitao founded the Morgellons Research Foundation (MRF) to raise awareness and secure research funding for the bizarre condition. Since then, nearly 14,000 families have reported Morgellons cases to MRF, although the actual number may be higher, the organization says.

To learn more about Morgellons, which many patients believe is caused by parasites, we consulted Michael Cappello, a pediatrics professor and infectious disease specialist at Yale University School of Medicine in New Haven, Conn.

[An edited transcript of the interview follows.]

What is Morgellons disease?
It is a skin condition that does not have an accepted medical definition. The name itself was given not by physicians per se—at least contemporary physicians—but by an advocacy group. [Leitao borrowed the name from 17th-century French doctors who observed a similar condition in children.]

What are the symptoms?

Patients complain of itching and scratching sensations. They get wrapped up in the belief that there is something beneath their skin—an infectious agent, such as a parasitic worm—that can be extracted. They often try to pull that something out of their skin, which creates open sores. Patients will say, "I scratched and I pulled this living thing out of my skin."

How do the patients describe these living things they believe are beneath their skin?
Often they describe them as tiny fibers. [According to the MRF, the fibers or "filaments" are "near microscopic" and may be white, blue, red or black. In addition to the filaments, there may also be black or white sandlike granules on or in the skin.].

Have you seen any evidence of these organisms?
Individuals and their physicians have sent me pictures of these filaments and skin samples purportedly containing them, but I have never found evidence of any parasites. Looking under the microscope, the samples look like amorphous skin, like a skin sample from a normal person might look. Some contain hair follicles. And apart from my personal experience, I am not aware of any evidence in the scientific literature suggesting that these patients have infectious agents crawling under their skin.

Do these patients have other signs of infectious disease?
Frequently, the patient's history and skin lesions are not consistent with what we know about infectious diseases. If, for example, a person had toxoplasmosis [a disease caused by the protozoan Toxoplasma gondii, often contracted via contact with soiled kitty litter, for example], he or she would have enlarged lymph nodes and flulike illness. Or if a patient had pinworm [a common parasitic infection in young children], he or she would have rectal itching. There are even parasitic infections that cause itching and skin manifestations, but none of them are consistent with the clinical presentation of Morgellons.

If there are no parasites, what else could cause the sores—some kind of skin disease?

To my knowledge, there is no consistent feature of these skin lesions that have been linked to a dermatological diagnosis. They are self-inflicted.

So what is wrong with these patients?
They are clearing suffering. My interpretation is that the symptoms are most consistent with a psychiatric condition.


Are there other characteristics of Morgellons besides the itching symptoms and skin lesions?
Patients often become extremely invested in studying their condition. I've had people who send me photographs tell me that they have invested thousands of dollars on very sophisticated microscopes to track these so-called organisms living in their skin. [According to the MRF, the condition also causes "joint pain, debilitating fatigue, changes in cognition, memory loss, mood disturbance and serious neurological manifestations."]

Does Morgellons affect certain demographic groups more than others—men, women, young, old, rich, poor?
Not that I am aware of.

How do you treat Morgellons?
Since I have not in any instance seen evidence of a parasitic infection among patients with these symptoms, I have not been able to treat them for parasitic disease. I think that at its core this is a psychiatric condition, but I am not a psychiatrist and cannot prescribe psychiatric medications. I usually tell the primary care physician to consider the diagnosis of delusional parasitosis [a condition in which patients mistakenly believe they are infested with parasites].

What advice would you give to a person who suspects he or she might have Morgellons?
I would suggest starting with a primary care physician and then consider seeing a psychiatrist if no dermatological or infectious condition can explain the symptoms.