To the Editor:

If we understand Dr. Ehrlich correctly, he takes issue with our article identifying subgroups of fibromyalgia (FM) patients based on the underlying mechanisms, because he 1) feels as though the FM label may cause more problems than it helps, and 2) is bothered by litigation and other contentious issues surrounding this diagnosis.

Before responding to these issues, it strikes us as odd that we need to do so. All rheumatic diseases are associated with some of the same underlying issues as those associated with FM. Most of our current “disease” criteria are defined largely upon historic notions of what constituted an illness, and those constructs have fundamental flaws if they are critically examined. However, although we endeavor to better understand any illness, these labels and constructs help us understand the underlying cause of a patient's symptoms, as well as how to treat the individual.

In osteoarthritis, for example, if the underlying “disease” is joint space narrowing and osteophyte formation, then why do 30–50% of patients in the population with the most severe forms of this disease (e.g., Kellgren/Lawrence grade 3 or 4 changes) have no pain or symptoms (1, 2)? In systemic lupus erythematosus (SLE), if the “disease” is characterized by immune complex formation and subsequent tissue damage, then why don't indices measuring the extent of disease activity or the damage correlate well with the symptoms SLE patients are experiencing (3–5)? When peer-reviewed scientific articles on the underlying mechanisms of these disorders are published in Arthritis & Rheumatism, the authors generally are not asked to address questions regarding the legitimacy of the underlying diagnosis.

As with these other rheumatic disorders, there is much we must learn regarding FM. However, just as with these other disorders, the overwhelming majority of patients who are given the FM label are helped: this reduces unnecessary further diagnostic testing and gives both patients and physicians a construct with which to help understand the underlying mechanisms and, most importantly, the most effective treatments. To illustrate this point, imagine if the American College of Rheumatology criteria for FM had not been established. We would have nothing to “call” individuals with the second most common rheumatic disease, and no way of standardizing studies elucidating the underlying mechanisms or most effective treatments. Would that really represent a better state of affairs?

The most unfortunate aspect of this letter, and editorials and opinion pieces in the same vein, is that they perpetuate many of the myths and stereotypes regarding FM that research have shown to be untrue (6, 7). The label of FM does not lead to an increase in the prevalence of FM, nor does it escalate illness behavior (8). In many patients with the FM syndrome, psychosocial factors play a role in symptom expression, but worsen symptoms only in some individuals. In fact, in our article, psychological factors appeared to make the underlying FM symptoms better rather than worse, in ∼20% of patients with FM. Finally, it is true that a small minority of patients with FM, just as with almost any other medical disorder, become overwhelmed by the demands of their illness and predicament and seek solace by applying for disability or pursuing legal action. The undersigned authors are just as troubled as Dr. Ehrlich by these “outliers” who become permanently disabled or receive large damages, but we differ in how we choose to respond to the problem.

Daniel J. Clauw MD*, David A. Williams PhD*, Richard H. Gracely PhD*, Thorsten Giesecke MD†, * University of Michigan, Ann Arbor, MI, † University of Cologne Cologne, Germany.