Fibromyalgia or Chronic Widespread Pain: Does It Matter?

Abstract

The question whether Fibromyalgia syndrome (FMS) is a distinct clinical entity in the context of chronic widespread pain (CWP) have remained challenging after decades of research and several diagnostic criteria that have attempted to clarify FMS. A recent study has raised more challenges on the issue, proposing that diagnosis of FMS in patients representing with CWP is not informative or helpful for clinical practice and such a differentiation will provide little or no significance regarding the choice of effective and safe therapies. This proposal will be further discussed here by reviewing the recent advances in the field of pain medicine. These advances have collectively provided compelling evidence that all individuals with chronic pain, even those classically categorized as originating from peripheral/nociceptive origins have common central contributions to their pain and associated comorbidities. The recent understanding of the pain mechanisms has also provided important implications on classification and management of pain. Centrally acting agents have been recommended as first-line treatment options for FMS and potential use of these agents has been expanded to other chronic pain disorders. After having reviewed the recent advances in the pain field, distinction between CWP and FMS still seems not to be useful in clinical practice, as effective treatment in an individual patient might be much guided by dominant underlying mechanisms rather than specific diagnosis the patient is suffering. The conditions representing with CWP in the absence of definitive objective confirmation may then be classified under one heading such as "CWP", "chronic pain syndrome" or "central pain", when considering their similar pattern of clinical presentation, commonality of central sensitization to their pathophysiology and their similar response to centrally acting analgesics. Future research should be directed toward classification of CWP based on the validated measurements of different aspects of pain. Such a classification may help clinicians identify the patients who will preferentially respond to peripheral or centrally acting analgesics and may therefore assist in advancing a more individualized and pain mechanism focused treatment in the clinical setting.