Is it necessary to strictly diagnose fibromyalgia syndrome in patients with chronic widespread pain?

The applicability of the American College of Rheumatology (ACR) 1990 and 2010 criteria for the diagnosis of fibromyalgia syndrome (FMS) was determined in 284 patients with chronic widespread pain (CWP) including those with regional and systemic painful disorders. On the basis of initial evaluation, patients were classified into three groups. Group 1, those without any comorbid disease (N = 105), group 2, those having regional non-inflammatory painful disorders (N = 104), and group 3, those with a diagnosis of an inflammatory rheumatic disease (N = 75). Overall, 65 % of the patients fulfilled the 1990 criteria, while 94 % of them fulfilled the 2010 criteria. Almost all of the patients (97 %) with CWP did meet at least one of the criteria set, regardless of whether they have accompanying painful disorders. Widespread pain index (WPI), symptom severity scale (SS), and fibromyalgia impact questionnaire (FIQ) scores were found to be significantly higher in the patients who satisfied the 1990 criteria than those who did not (P < 0.001). Tender point counts were found to be significantly correlated with WPI, SS, FIQ, and Beck depression inventory (BDI) scores (P < 0.001). The findings of the study support the suggestion that FMS is just a continuum of CWP, rather than a distinct diagnostic entity. As treatment of FMS is usually identical with that of CWP, strict diagnosis of FMS will provide little or no significance from the viewpoint of clinical practice. We suggest that future research should be directed toward classification of CWP to provide guidance to clinicians in selecting effective therapies.