Fibromyalgia: Do not give up the tender point count too easily: Comment on the article by Wolfe et al

We read with interest the article by Wolfe et al (1) and the editorial by Wolfe (2), published recently in Arthritis Care & Research, introducing new diagnostic criteria for the fibromyalgia syndrome. These preliminary diagnostic criteria (including a widespread pain index [WPI] 7 and a symptom severity [SS] scale score of 5, or a WPI of 3–6 and an SS scale score of 9) raise important concerns. First, the new criteria are intended to get rid of the tender point examination introduced in 1990 by the American College of Rheumatology (ACR) (3). Abandoning an intrinsic requirement for physical examination in favor of indices and scales carries the risk of discarding the “laying on of hands” and a careful clinical examination altogether. Indeed, the physician who regards the tender point examination as cumbersome may think the same of a thorough rheumatologic and neurologic examination and limit the clinical encounter to a structured interview. Yet, multifocal pain has a broad differential diagnosis, relying on careful history taking and clinical examination. Also, the tenderness to palpitations in specific anatomic locations lends credibility to the fibromyalgia concept. Moreover, the article clearly shows that the tender point count is the most reliable feature to differentiate fibromyalgia and nonfibromyalgia patients. We do not believe that the 11 of 18 tender points requirement is a sacred threshold or that the patient with widespread pain and 8 tender points should be treated any differently from the patient with 15 tender points. However, by discarding the tender point count, this new definition risks throwing out the baby with the bathwater. Second, the new diagnostic criteria, as opposed to the ACR 1990 classification criteria, implicitly state that fibromyalgia should be a diagnosis of exclusion, without detailing what painful disorders should be ruled out or what tests should be performed for that reason. In contrast, the 1990 classification criteria made no exclusions for the presence of concomitant radiographic or laboratory abnormalities and abandoned the distinction between primary fibromyalgia and secondary-concomitant fibromyalgia (3). Third, the control group consisted of patients with noninflammatory painful rheumatic disorders. The proportion of control persons with a fibromyalgia diagnosis increased 4-fold (from 2.0% using the 1990 criteria to 9.1% using the new criteria). One can only wonder how the new criteria will perform in patients with other central or chronic pain disorders, or with neuropsychiatric disorders. For example, many chronic pain patients report multifocal pain and associated nonpain symptoms such as fatigue, unrefreshed sleep, mood disturbance, and cognitive difficulties. In other words, the present preliminary criteria need external validation against other patient groups and outside the rheumatology setting. Otherwise, we risk lumping together many patients with so-called functional somatic syndromes or central hypersensitivity states, as well as chronic pain. Abandoning the tender point count may open Pandora’s Box. Fourth, the mean age (54.6 years) of the fibromyalgia study subjects suggests that many had the label for quite some time. Actually, a fair share of subjects ended up in the “prior fibromyalgia” category. Testing diagnostic criteria in a group with shorter durations of symptoms may be more clinically relevant. Fifth, the authors state that the present preliminary criteria are not meant to replace the ACR 1990 classification criteria. Moreover, many patients entering the present study as fibromyalgia patients were labeled as such not based on the ACR classification criteria, but on the personal judgment of the study physician. The coexistence of several sets of criteria (ACR classification criteria, personal opinion, a WPI of 7 and an SS scale score of 5, or a WPI of 3–6 and an SS scale score of 9) will not enlighten the field. If everyone is free to choose his or her preferred set of criteria, a 20-year journey will continue in the fog.