I get asked all the time what I think about the CDC study on Morgellons Disease. If you’ve seen anything I’ve written or heard me talk about Morgellons, you’ve probably figured out that I’m not a huge fan of it. I wouldn’t be doing this research if I was. With that said, some of what they did was good research. The problem is that it was flawed from the beginning, so even the good things they did don’t really matter in terms of believing the conclusion that many people have made. Somehow this small, flawed study that was never meant to be definitive in terms of identifying what Morgellons Disease is became the seminal study defining the condition. It was never meant to be so and was not set up that way. Here’s my take on the study from the perspective of a someone who has been conducting various types of medical research for over 20 years and has been NIH-funded the entire time. The perspective I’m using is that of a peer reviewer, though obviously I was not one of the people who peer reviewed this one. The following is modified from the draft of our book that we sent to the publisher.
The Centers for Disease Control and Prevention Study
The study that is cited as the authoritative source for naming Morgellons Disease as delusional infestation or delusions of parasitosis is the study done by the Centers for Disease Control and Prevention that was published in 2012 by Pearson et al. The primary conclusion of this study was as follows: “This unexplained dermopathy was rare among this population of Northern California residents but associated with significantly reduced health-related quality of life. No common underlying medical condition or infectious source was identified, similar to more commonly recognized conditions such as delusional infestation” (taken from the abstract of the study).
The first thing to note about this conclusion is that it is not definitive. It states that no infectious or other physical source of the disease was found and that it was similar to delusional infestation. That is not the same thing as the determination of a definitive etiology and it is not worded that way. The next thing to notice is that this rare condition was studied in one Northern California population. This is not a large-scale epidemiologic study that would allow for a definitive determination of etiology and does not include any study of potential biological mechanisms behind the condition. This is appropriate for an initial exploratory study that would lead to further research. Thus, we go into an examination of the methodology and results already knowing that this study is not a definitive one.
As we continue examination of this study, we see that the authors state that the condition is not recognized as a distinct clinical disorder nor does it have established diagnostic criteria. In the same sentence, the authors state that “many dermatologists consider the condition to be synonymous with delusional parasitosis (DP)”. They go on to say that there have been isolated case reports and anecdotal accounts and that a range of potential infectious and non-infectious etiologies have been proposed but none have been proven. It should be noted that at this time, there had been several publications by Dr. Ginger Savely and others in the same group of researchers, likely the reported isolated and anecdotal accounts. One of these was Savely and Stricker (2010) and was based on a case series of 122 clinical cases from Savely’s own practice in Texas that had confirmed filaments coming from the skin that were not textile in nature (V.R. Savely and Stricker 2010).
The Centers for Disease Control and Prevention study was done with enrollees of Kaiser Permanente of Northern California that represented about 30% of the local population. There is no mention of a physician within the group with clinical experience specifically examining Morgellons filaments or the disease itself. This was a case series study that included a cross-sectional survey, clinical evaluations and histopathologic studies, again with no mention of a clinician with specific expertise on the illness through extensive or any clinical experience.
Cases of the disease were identified as individuals age 13 or older who had received care through the network between July 1, 2006, and June 30, 2008, and “reported fibers, threads, specks, dots, fuzzballs, granules or other forms of solid material coming out of his/her skin; AND one or both of the following:
A skin lesion such as a rash, wound, ulcer, or nodule; OR
A disturbing skin symptom such as pruritus, feeling that something is crawling on top of or under the skin, or stinging, biting, or a pins and needles sensation” (p.2)
Cases were identified through electronic health records searching for these types of words in the progress notes or were coded in the record as ICD-9-C code 300.29, which translates to delusions, parasitosis. Patients had to have been seen in dermatology, psychiatry, infectious diseases, pediatrics, or primary care. Potential patients were screened via telephone for participation; additional patients who self-identified and asked to be included were also screened by telephone but were not included in estimates of prevalence. Essentially, this means that the research team looked for patients who had been diagnosed with delusional parasitosis or could be diagnosed that way for inclusion in their study and only included those who were diagnosed as such in their prevalence analysis.
Patients who were enrolled completed an internet-based self-administered survey or an administered telephone-based survey to collect fairly robust information about medical, social, and environmental factors. The study does not state whether the patients were asked explicitly about exposure to B. burgdorferi (though blood testing was done later for those patients who received an examination). Given that this possibility was already in the literature, as admitted by the authors in their introduction, it seems remiss that patients would not be asked about this explicitly, with the findings reported in this case series.
Patients age 18 or older who self-reported active skin symptoms within the past two weeks were brought in for clinical examination. Internists completed a medical history and physical examination of each patient. A dermatologist then completed a separate examination of patients’ skin which included collection of skin biopsies, including both normal and abnormal skin, and any fibers or other material present. Medical photographs of the lesions and overall skin condition were also taken. Patients also provided blood, urine and hair samples and underwent a large battery of standardized neurocognitive and neuropsychiatric testing.
Blood and urine samples were tested for a variety of infectious agents, including the accepted, albeit problematic, 2-stage testing for Lyme disease. Urine and hair samples were also tested for several different types of drug abuse because of the association between formication and drug use. Biopsied skin and swabs from open sores were also examined for infectious agents, as well as the types of cellular changes present. Finally, the fibers collected were tested for composition.
There are many pieces of this study that were done well, particularly the very detailed examinations and history of patients through both surveys and clinician encounters. The amount of testing that was done is impressive and many different possibilities were considered in the testing, including many infectious agents, psychiatric possibilities and more. The problems with this study go back to the early stages of the research, particularly sampling frame and determination of who the case patients are, as well as sample size and distribution.
The research team started with a possible 467 cases, which were whittled down to 115 through further examination of eligibility criteria and people who did not respond. From there, an additional 6 declined participation and 39 failed to complete the survey after they had initially agreed to participate. This left them with 70 individuals completing the survey. Of these, 41 participated in the clinical evaluation. This is normal for medical research; the number of individuals who participate is always significantly lower than the initial possibly eligible patients. The problem is that this small sample size for a condition that is so poorly understood does not allow for any clear statements about cause or even symptoms.
Another issue with the sample is that all of these individuals are from a very small geographic area and the condition being studied is global. This leads to the likely possibility of a biased sample. The authors claim that they have a representative sample that can lead to prevalence estimates. We would argue that they may be able to provide prevalence estimates in the Kaiser Permanente patient population of that specific geographic area and for that time frame, but the problematic way in which patients were identified precludes even that estimate.
The results of this study provide some insight into a group of patients who may or may not have Morgellons Disease. It is possible that other patients who believe they have Morgellons would provide similar results; it is also possible that they would not. The results are difficult to interpret because of the problems in the early methods of the study. If similar methods for clinical evaluation were used with a larger sample of Morgellons patients identified by providers with clinical experience with the condition and a definition of Morgellons Disease that is less biased towards a psychiatric condition, we may be able to learn more. Using this study as the definitive study of Morgellons Disease is wholly inappropriate. The authors themselves conclude: “We were not able to conclude based on this study whether this unexplained dermopathy represents a new condition, as has been proposed by those who use the term Morgellons, or wider recognition of an existing condition such as delusional infestation, with which it shares a number of clinical and epidemiologic features” (p.11).
The authors do, however, make it clear through their definitions and sampling techniques, as well as their writing, that they were biased towards a psychiatric cause. This fact, in and of itself, mandates that additional research be done, preferably by a team with representation of multiple views of what Morgellons Disease may be.
Those are my thoughts and should not be considered definitive nor “correct”. Take them or leave them.
References:
Pearson, M. L., J. V. Selby, K. A. Katz, V. Cantrell, C. R. Braden, M. E. Parise, C. D. Paddock, M. R. Lewin-Smith, V. F. Kalasinsky, F. C. Goldstein, A. W. Hightower, A. Papier, B. Lewis, S. Motipara, and M. L. Eberhard. 2012. "Clinical, epidemiologic, histopathologic and molecular features of an unexplained dermopathy." PLoS One 7 (1): e29908. https://doi.org/10.1371/journal.pone.0029908.
Savely, Virginia R, and Raphael B Stricker. 2010. “Morgellons disease: analysis of a population with clinically confirmed microscopic subcutaneous fibers of unknown etiology.” Clinical, cosmetic and investigational dermatology: 67–78.