Myofascial pain, fibromyalgia or fibrositis?
The terms myofascial pain, fibromyalgia and fibrositis are critically examined. They constitute diagnostic labels for non-specific musculoskeletal aches and pains. Analysis of the evidence shows that none of these labels is substantiated by hard physical signs or by laboratory evidence of consistent pathological or biochemical abnormality. What is the objective evidence for disorder(s) of muscle, fascia or fibrous tissues, so clearly indicated by these diagnostic names? Alternative terms such as 'regional pain syndrome' or 'chronic pain syndrome' merely redefine the clinical problem without providing a mechanism or basis for diagnosis. Despite different diagnostic criteria, these conditions, along with chronic fatigue syndrome, have many demographic and clinical similarities, most notably tender trigger points. Indeed, the terms are often used interchangeably. There are few differences in the symptoms, physical findings, laboratory tests, functional status, psychosocial features and psychiatric disorders. This paper seeks not to deny the existence of aches and pains, but to critically examine the utility of these terms. The only claimed physical sign is the presence of tender trigger points over muscles or muscle attachments. Research suggests that tender points are a measure of general distress related to pain complaints but separately associated with fatigue and depression. They are present in some normal subjects and are variable in occurrence in time in the same individual. They reflect no demonstrable pathology. It is therefore argued that none of these commonly used diagnoses represent distinct disease entities. A possible but unproven alternative hypothesis is that such symptoms relate to neural pain with both peripheral and central components, and in some instances psychological or wilful embellishment.