What is fibromyalgia and why is it (still) controversial?
In 1987, DL Goldenberg published a paper in JAMA, “Fibromyalgia syndrome. An emerging but controversial condition.” [JAMA. 1987 May 22-29;257(20):2782-7.] Nearly three dozen years later, fibromyalgia has fully emerged, but is no less controversial.
In general, a diagnosis may be controversial because there is disagreement about what causes it, how to diagnose it, or how to treat it. In the case of fibromyalgia, all three apply, but there is a deeper source of controversy: the disease is poorly understood. (A Google query for the phrase fibromyalgia 'poorly understood' gets 170,000 hits in January, 2021)
Here are the basics regarding fibromyalgia:
- The American College of Rheumatology (as of 2020) defines fibromyalgia as “a common neurologic health problem” featuring widespread pain and tenderness that appears in different places and at different times.
- The diagnosis of fibromyalgia is based on the clinical presentation of widespread pain and tenderness and the exclusion of other conditions that may cause overlapping symptoms. (Tenderness at a specific number of specific points is no longer a diagnostic criterion.)
- Fatigue and disorders of sleep are common.
- Fibromyalgia is thought to be found in about 2% of adults; females are more commonly affected than males.
- There is no objective examination (such as a radiograph or laboratory test) to diagnose fibromyalgia.
- The differential diagnosis includes inflammatory and crystalline arthropathies, sleep disorders, depression, endocrine disorders (particularly hypothyroidism) and polymyalgia rheumatica.
- There is no cure for fibromyalgia. Treatment is supportive and should address the presenting symptoms.
- The U.S. Food and Drug Administration has approved three drugs for the treatment of fibromyalgia: duloxetine (Cymbalta), milnacipran (Savella), and pregabalin (Lyrica).
- Physical activity, meditation, and avoidance of symptom triggers have shown to reduce symptoms.
- Narcotics are not indicated.
- Patients presenting with signs and symptoms of depression should be screened for suicidal ideation and referred appropriately.
Elements of controversy:
- Fibromyalgia cannot be established with an objective laboratory test or imaging. Musculoskeletal fields rely heavily on objective evidence such as radiographs and laboratory tests. Accordingly, to some musculoskeletal practitioners, the lack of such evidence may cast doubt on the validity of the diagnosis.
- The underlying pathophysiology of fibromyalgia remains largely unclear. The most widely supported mechanism is a concept known as “central sensitization,” when central nervous system pain processing becomes dysfunctional and leads to increased sensitivity to pain. This is supported by some, but not all, studies of cerebrospinal fluid and functional magnetic resonance imaging.
- Many of the presenting symptoms are suggestive of psychological overlay, including ubiquitous pain with a lack of objective signs such as swelling, warmth, or erythema; hyperalgesia (abnormally low pain threshold); allodynia (pain with tactile stimuli that would normally not be painful, such as brushing the skin); hypersensitivity to bright light, loud noise, and odors; sleep disorders; and symptoms of depression and anxiety.