Fibromyalgia Pain

Assessment and Diagnosis of Fibromyalgia

In the primary care setting, the diagnosis of fibromyalgia can usually be made from the history and examination. The patient reports widespread pain, fatigue, and associated symptoms such as sleep disturbances and headaches.⁵⁴ The characteristic feature on physical examination is the demonstration of specific tender points. Tenderness is elicited with remarkably light pressure, an amount of force necessary to blanche a fingernail. The research criteria for defining fibromyalgia developed by the ACR indicate that the diagnosis requires pain in 4 body quadrants (i.e., left and right side of the body, above the waist, and below the waist) and axial skeletal pain lasting 3 or more months, with tenderness in 11 of 18 specific locations.⁵⁵ Many patients who have a pain syndrome that is characterized by diffuse pain and stiffness, and other features, do not have the classic pattern of tender points. Some clinicians diagnose these patients as having fibromyalgia and others use the term chronic widespread pain syndrome. Regardless, these patients have multifocal pain in many sites of the body, which cannot be explained by any other disorder.

The diagnosis of fibromyalgia may be complicated by comorbid conditions such as rheumatoid arthritis or the spondyloarthropathies. Most patients report that persistent pain and fatigue adversely affect their quality-of-life; there is strong evidence that major depression is associated with fibromyalgia.⁵⁶ Fibromyalgia often coexists with other ill-defined syndromes such as chronic fatigue syndrome, headache syndromes, and irritable bowel syndrome. The Fibromyalgia Impact Questionnaire (FIQ)⁵⁷ is an instrument designed to quantitate the overall impact of fibromyalgia over many dimensions (e.g., function, pain level, fatigue, sleep disturbance, psychological distress, etc.). It is scored from 0 to 100 with the latter number being the worst case. The average score for patients seen in tertiary care settings is about 50. The FIQ is used to assess change in fibromyalgia status.