Recently, the Centers for Disease Control and Prevention (CDC) decided to launch a detailed study into the nature of Morgellons, also known as unexplained dermopathy. On their website they write:

Considering the complexity of this condition, we believe that a measured and thorough approach offers the best chance for finding useful answers. To learn more about this condition, CDC is conducting an epidemiologic investigation.

Morgellons is certainly a very interesting medical entity, as the many questions I have received about this enigmatic condition indicate. Briefly, those who suffer from Morgellons have a chronic sense of itching and tingling under their skin. This sensation leads to scratching. The dermatological manifestations include open sores, and there have been reports of strange fibers extruding from these sores. Sufferers also often exhibit psychiatric symptoms, such as anxiety.

There are two schools of thought about what is the true nature of Morgellons. One side, including the Morgellons Research Foundation, advocates the position that “Morgellons disease” is an infectious disease, primarily a skin infection. The infection leads to the itching sensation, the sores, and the strange fibers. The constant irritating sensation also leads secondarily to the psychiatric symptoms. They cite evidence linking Morgellons to Lyme disease, and note that sufferers often respond to prolonged antibiotic use.

The other side believes that the psychiatric symptoms are primary, a form of delusional parasitosis – or the belief that one is infected with parasites. The skin sensation is therefore a somatic (sensory) delusion, leading to chronic itching that causes the skin manifestations. The strange fibers are simply fibers from clothing worked into open sores, and sometimes even healed into healing sores. Analysis of the fibers has shown that they are often consistent with various textiles, and that they are not biological in nature. Any bacteria found in the sores are incidental and not causative, and response to antibiotics is incomplete which is more compatible with a placebo effect than a true antibiotic effect.

Those are pretty stark battle lines, but fortunately they lead to very distinct predictions. It should, therefore, be possible to sort out which hypothesis is correct with fairly objective evidence. This kind of debate happens within medicine all the time, and eventually they get sorted out with evidence. The CDC investigation is not likely to be definitive by itself – but it seems that it will add significantly to the discussion.

Which side is more likely to be correct? First, I think it is important to note that neither side can be ruled out a-priori. It is certainly possible that an unknown infection (or other etiology) is causing chronic pathological itching in the skin. This can be what we call a neuropathic symptom – inflamed, damaged, or otherwise irritated nerves endings can generate abnormal sensory signals that are either painful or feel like itching or tingling. This then leads to scratching and all the other manifestations of Morgellons. This is a plausible scenario.

However, we must assess the fibers as a separate question. I think the only plausible explanation for the presence of fibers in the lesions is that they are from clothing. I do not think we need to hypothesize any exotic biological process to explain the creation of these textile-like fibers.

I also feel that the delusional parasitosis hypothesis is also very plausible and can explain all aspects of Morgellons, as I noted above. The evidence that proponents of the infectious hypothesis point to in order to claim that a primary psychiatric disorder is not a viable explanation is primarily the apparent response to antibiotics. However, this is far from definitive.

I am suspicious of a partial and temporary response to antibiotics. I think this is more likely to be a placebo effect. It is very interesting that proponents link this to Lyme disease, since there is a similar grass roots organization of patients who believe they have chronic Lyme infection and need prolonged antibiotics that produce a partial and temporary response. The linking of one dubious chronic infection to another does not add credibility to the infection hypothesis. (Note that I am not questioning the legitimacy of Lyme disease itself, just a chronic undetectable form of the disease that requires prolonged antibiotic therapy. Here is a more thorough treatment of this topic.)

Finding bacteria in the wounds of some Morgellons patients also is not very convincing, since any open skin lesion is likely to be teeming with bacteria.

We must also consider that there may be some truth to both hypotheses, or that different patients identified as Morgellons may have different entities – it may not all be one diagnosis. So perhaps some patients have delusional parasitosis, while others have a chronic itching type of neuropathic pain syndrome. At this point I am most suspicious of the fibers as evidence – as I stated I think they are just fibers from clothing. I am also not convinced by the evidence so far for an infectious cause.

It is important not to commit prematurely to either hypothesis nor to oversimplify – typically in medicine the full story turns out to be more complex than anyone initially thinks. It can be counterproductive for proponents of the delusional parasitosis hypothesis to fail to consider other possibilities because they are put off by fallacious arguments on the other side. It is also counterproductive for proponents of the infectious hypothesis to dismiss skepticism as closed-mindedness rather than a pathway to the truth, and I think that many of them are falling into this trap.

For example, here is an exerpt from an editorial published by William T. Harvey, a member of the medical advisory board of the Morgellons Research Foundation:

Serious students of the most basic sciences learn early that reality is the singular essence of each. “Truth” in this context is simply a semantic label given to current human understanding of that reality. Human truth never reaches reality, but as the Ancient Mariner, drifts forever, perhaps asymptotically approaching what is real. So it is with medical truth. Yesterday’s texts are already trash, placing an enormous burden on each of us to look beyond our passed-on guidebooks, created as best they could be with the tools and knowledge available at the time.

He uses this high-handed discussion of “truth” as a basis to criticize all those who would dare to be skeptical of the infectious hypothesis. It sets a tone for counterproductive confrontation – not consensus building through objective research.

I also think that at this point using the term “Morgellons disease” is premature and counterproductive. The term “disease” should be reserved for pathophysiological entities – where we have a known cause of a specific syndrome. What we have now is at best a clinical syndrome. Terminology in science is important, for it can often constrain our thinking about a topic. Proponents of the infectious hypothesis are trying to achieve through terminology what they have not yet achieved through scientific research.

At this point my personal bias is that Morgellons will turn out to be mostly a primary psychiatric disorder. It is possible that some people with this label may turn out to have a chronic neuropathic syndrome, which may in turn have one of various causes. I give the infectious hypothesis a low probability at this point, I think the pattern is most consistent with a cultural phenomenon – a belief promoted at the grass roots level, aided by the Internet, driven more by belief than evidence and developing an unhealthy resistance to skepticism.

However, I am also completely willing to change my mind as new evidence comes in. Researching Morgellons can theoretically be useful to resolve the debate. However, the rhetoric of the believers is concerning as it reminds me of other situations in which a specific belief or hypothesis became embedded within a group of proponents prior to being established scientifically. The group then becomes invested in the belief and is therefore highly resistant to change.

They will likely have their day of reckoning – when fairly definitive evidence calls into question the infectious hypothesis. At that time they will either stay true to science and adapt to the evidence, or they will declare themselves to be a fringe ideological group (as have, say, those who believe thimerosal in vaccines causes autism). History teaches pessimism – but we’ll just have to wait and see.