Fibromyalgia

Essentials of Diagnosis

• Most frequent in women aged 20–50

• Chronic widespread musculoskeletal pain syndrome with multiple tender points

• Fatigue, headaches, numbness common

• Objective signs of inflammation absent; laboratory studies normal

General Considerations

• Affects 3–10% of the general population

• Cause is unknown, but aberrant perception of painful stimuli, sleep disorders, depression, and viral infections have all been proposed

• Shares many features with the myalgic encephalomyelitis/chronic fatigue syndrome

  • An increased frequency among women aged 20–50

  • Absence of objective findings

  • Absence of diagnostic laboratory test results

• While many of the clinical features of the two conditions overlap, musculoskeletal pain predominates in fibromyalgia whereas lassitude dominates the myalgic encephalomyelitis/chronic fatigue syndrome

• Fibromyalgia can be a complication of hypothyroidism, rheumatoid arthritis or, in men, sleep apnea

Symptoms and Signs

• Chronic aching pain and stiffness, frequently involving the entire body but with prominence of pain around the neck, shoulders, low back, and hips

• Fatigue, sleep disorders, subjective numbness, chronic headaches, and irritable bowel symptoms are common

• Even minor exertion aggravates pain and increases fatigue

• Physical examination is normal except for "trigger points" of pain produced by palpation of various areas such as

  • Trapezius

  • Medial fat pad of the knee

  • Lateral epicondyle of the elbow

Differential Diagnosis

• Rheumatoid arthritis

• Systemic lupus erythematosus

• Polymyositis produces weakness rather than pain

• Polymyalgia rheumatica

  • Produces shoulder and girdle pain

  • Is associated with an elevated sedimentation rate and anemia

  • Occurs after age 50

• Hypophosphatemic states, such as oncogenic osteomalacia

• Diagnosis of exclusion

• Thyroid function tests are useful because hypothyroidism can produce a secondary fibromyalgia syndrome

Conservative Measures

• Patient education is essential; while therapies are imperfect, course is not progressive

• Cognitive behavioral therapy, including programs that emphasize mindfulness meditation, is often helpful

• Exercise programs are also beneficial, particularly tai chi and yoga

Medications

• The following have modest efficacy:

  • Fluoxetine

  • Duloxetine

  • Milnacipran

  • Cyclobenzaprine

  • Pregabalin

  • Gabapentin

  • Low-dose naltrexone

• Nonsteroidal anti-inflammatory drugs are generally ineffective

• Tramadol and acetaminophen combinations have ameliorated symptoms modestly in short-term trials

• Opioids and corticosteroids are ineffective and should not be used to treat fibromyalgia

Prognosis

• All patients have chronic symptoms

• With treatment, however, many do eventually resume increased activities

• Progressive or objective findings do not develop