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 Temporomandibular Disorders: 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.

Symptoms and Signs

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.

Diagnosis

• Clinical criteria
• Usually testing to exclude other disorders

Fibromyalgia is suspected in patients with the following:

• Generalized pain and tenderness, especially if disproportionate to physical findings
• Negative laboratory results despite widespread symptoms
• Fatigue as the predominant symptom

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 Fig. 1: Bursa, Muscle, and Tendon Disorders: 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.

Fig. 1
Diagnosing fibromyalgia Diagnosis is based on the following: Pain elicited by palpation of specific tender points: A specific number of tender points (≥ 11 of 18) is no longer required for diagnosis but may indicate more recalcitrant pain. Digital palpation should be done with a force of about 4 kg. A positive result requires that palpation be painful. A history of widespread pain for at least 3 mo: Pain is considered widespread when patients have pain in the left and right side of the body, above and below the waist, and in the axial skeleton (cervical spine, anterior chest or thoracic spine, or low back).

To avoid potential pitfalls, clinicians should consider the following:

• Fibromyalgia is often overlooked in men, children, and adolescents.
• Chronic fatigue syndrome (see Syndromes of Uncertain Origin: Chronic Fatigue Syndrome) can cause similar generalized myalgias and fatigue and laboratory test results are typically normal.
• Polymyalgia rheumatica (see Vasculitis: 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.

Pearls & Pitfalls In patients with increased stiffness and pain, consider fibromyalgia as well as an exacerbation of any known systemic rheumatic disorder such as RA or SLE.

Prognosis

Fibromyalgia tends to be chronic but may remit spontaneously if stress decreases. It can also recur at frequent intervals. Functional prognosis is usually favorable for patients being treated with a comprehensive, supportive program, although symptoms tend to persist to some degree.

Treatment

• Stretching and aerobic exercise, local heat, and massage
• Stress management
• Tricyclic antidepressants or cyclobenzaprineSome Trade Names
  FLEXERIL
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  to improve sleep
• Nonopioid analgesics

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, amitriptylineSome Trade Names
ELAVIL
ENDEP
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10 to 50 mg, trazodoneSome Trade Names
DESYREL
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50 to 150 mg, doxepinSome Trade Names
SINEQUAN
ZONALON
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10 to 25 mg) or the pharmacologically similar cyclobenzaprineSome Trade Names
FLEXERIL
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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, tramadolSome Trade Names
ULTRAM
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, acetaminophenSome Trade Names
GENAPAP
TYLENOL
VALORIN
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, NSAIDs) may help some patients. Opioids should be avoided. Pregabalin, duloxetineSome Trade Names
CYMBALTA
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, 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% bupivacaineSome Trade Names
MARCAINE
SENSORCAINE
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or 1% lidocaineSome Trade Names
XYLOCAINE
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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.

Key Points

• 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.

Last full review/revision February 2013 by Joseph J. Biundo, MD

Content last modified March 2013