* This is the Professional Version. *
(Myofascial Pain Syndrome; Fibrositis; Fibromyositis)
Fibromyalgia is a common nonarticular disorder of unknown cause characterized by generalized aching (sometimes severe); widespread tenderness of muscles, areas around tendon insertions, and adjacent soft tissues; muscle stiffness; fatigue; and poor sleep. Diagnosis is clinical. Treatment includes exercise, local heat, stress management, drugs to improve sleep, and analgesics.
In fibromyalgia, any fibromuscular tissues may be involved, especially those of the occiput, neck, shoulders, thorax, low back, and thighs. There is no specific histologic abnormality. Symptoms and signs are generalized, in contrast to localized soft-tissue pain and tenderness (myofascial pain syndrome—see also Myofascial Pain Syndrome), which is often related to overuse or microtrauma.
Fibromyalgia is common; it is about 7 times more common among women, usually young or middle-aged women, but can occur in men, children, and adolescents. Because of the sex difference, it is sometimes overlooked in men. It sometimes occurs in patients with systemic rheumatic disorders.
Current evidence suggests fibromyalgia may be a centrally mediated disorder of pain sensitivity. The cause is unknown, but disruption of stage 4 sleep may contribute, as can emotional stress. Patients may tend to be perfectionists. Fibromyalgia may be precipitated by a viral or other systemic infection (eg, Lyme disease) or a traumatic event.
Stiffness and pain frequently begin gradually and diffusely and have an achy quality. Symptoms can be exacerbated by environmental or emotional stress, poor sleep, trauma, or exposure to dampness or cold or by a physician who implies that the disorder is “all in the head.”
Patients tend to be stressed, tense, anxious, fatigued, ambitious, and sometimes depressed. Many patients also have irritable bowel syndrome symptoms, interstitial cystitis, or migraine or tension headaches. Pain may worsen with fatigue, muscle strain, or overuse. Specific, discrete areas of muscle (tender points) may be tender when palpated.
Fibromyalgia is suspected in patients with the following:
Tests should include ESR or C-reactive protein, CK, and probably tests for hypothyroidism and hepatitis C (which can cause fatigue and generalized myalgias). The diagnosis is based on clinical criteria, including tenderness at some of the 18 specified tender points (see see Figure: Diagnosing fibromyalgia). Most experts no longer require a specific number of tender points to make the diagnosis, as originally proposed (≥ 11 of 18). Patients with only some of the specified features may still have fibromyalgia.
To avoid potential pitfalls, clinicians should consider the following:
Fibromyalgia is often overlooked in men, children, and adolescents.
Chronic fatigue syndrome (see Chronic Fatigue Syndrome) can cause similar generalized myalgias and fatigue and laboratory test results are typically normal.
Polymyalgia rheumatica (see Polymyalgia Rheumatica) can cause generalized myalgias, particularly in older adults; it can be distinguished because it tends to affect proximal muscles selectively, and ESR is high.
In patients with systemic rheumatic disorders, diagnosing coexistent fibromyalgia may be more difficult. For example, fibromyalgia may be misinterpreted as an exacerbation of RA or SLE.
Stretching exercises, aerobic exercises, sufficient sound sleep, local applications of heat, and gentle massage may provide relief. Overall stress management (eg, deep breathing exercises, meditation, psychologic support, counseling if necessary) is important.
Exercises to gently stretch the affected muscles should be done daily; stretches should be held for about 30 sec and repeated about 5 times. Aerobic exercise (eg, fast walking, swimming, exercise bicycle) can lessen symptoms.
Improving sleep is critical. Drugs can be taken but only at night and only to improve sleep. Low-dose oral tricyclic antidepressants at bedtime (eg, amitriptyline 10 to 50 mg, trazodone 50 to 150 mg, doxepin 10 to 25 mg) or the pharmacologically similar cyclobenzaprine 10 to 40 mg may promote deeper sleep and decrease muscle pain. The lowest effective dose should be used. Drowsiness, dry mouth, and other adverse effects may make some or all of these drugs intolerable, particularly for the elderly.
Nonopioid analgesics (eg, tramadol, acetaminophen, NSAIDs) may help some patients. Opioids should be avoided. Pregabalin, duloxetine, and milnacipran are available for treatment of fibromyalgia, but should be used only as adjuncts to exercise, measures to improve sleep, and stress management, may help reduce pain.
Occasional injections of 0.5% bupivacaine or 1% lidocaine 1 to 5 mL are used to treat incapacitating areas of focal tenderness, but such injections should not be relied on as primary treatment because evidence does not support their regular use.
Drugs taken by the patient should be reviewed to identify those that may aggravate sleep problems. Such drugs should be avoided. Anxiety,depression, and especially bipolar disorder, if present, should be addressed.
Fibromyalgia-related stiffness and pain can be exacerbated by environmental or emotional stress, poor sleep, trauma, or exposure to dampness or cold or by a physician who implies that the disorder is “all in the head.”
Suspect fibromyalgia when generalized pain and tenderness and fatigue are unexplained or out of proportion to physical and laboratory findings.
Do ESR or C-reactive protein, CK, and tests for hypothyroidism and hepatitis C, and consider chronic fatigue syndrome and polymyalgia rheumatica.
Consider fibromyalgia in patients having apparent exacerbations of systemic rheumatic disorders such as RA or SLE.
Treat by emphasizing physical methods, stress management, and sleep improvement, and, when necessary for pain, by giving nonopioid analgesics.
* This is the Professional Version. *