Fibromyalgia Pain

Assessment and Diagnosis of Fibromyalgia

In the primary care setting, the diagnosis of fibromyalgia can usually be made with a careful pain history, supplemented with pain diagrams. The patient will have widespread pain, fatigue, and associated symptoms such as sleep disturbances and headaches.⁶⁰ The characteristic feature on physical examination is the demonstration of specific tender points that are remarkably constant in their location. The research criteria for defining fibromyalgia developed by the ACR may be helpful in guiding diagnosis. While not all patients with fibromyalgia meet these criteria, the ACR defines fibromyalgia as widespread 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.⁶¹ The multifocal nature of this pain condition combined with generalized allodynia/hyperalgesia distinguishes it from other conditions with persistent musculoskeletal pain.

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.⁶² Fibromyalgia often coexists with other ill-defined syndromes such as chronic fatigue syndrome, headache syndromes, and irritable bowel syndrome.⁶⁰ The Fibromyalgia Impact Questionnaire (FIQ)⁶³ 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.