Fibromyalgia – Diagnosis, Symptoms, and Treatment

What is Fibromyalgia?

Fibromyalgia is a medical condition characterized by diffuse muscle and joint pain, abnormal sensations, fatigue, and impaired sleep.  The disease frequently coexists with other functional somatic conditions such as irritable bowel syndrome, chronic headache, and psychiatric disorders.  It most often affects women age 20-50.

The cause of fibromyalgia is not entirely clear but may be related to alterations in pain processing by the central nervous system, which results in chronic pain and sensory abnormalities.  There are no specific tests to make the diagnosis – studies are typically obtained to rule out other disorders such as inflammatory arthritis and myopathy.

What Causes Fibromyalgia?

The cause of fibromyalgia is not known.  The disease is likely related to specific genetic and environmental factors that lead to chronic nerve irritation and pain.  Experts believe that this occurs due to alterations in pain processing by the central nervous system.  This results in pain all over the body and abnormal sensory symptoms such as numbness and tingling.

How Common is Fibromyalgia?

Fibromyalgia is a relatively common condition that is often evaluated in the primary care clinic.  Severe or atypical cases of the disease often require referral to a rheumatology specialist, especially if first-line measures are unsuccessful.

Fibromyalgia is the most common cause of diffuse musculoskeletal pain in young to middle-aged women.  It is 6 times more common in women compared to men.  The condition has a prevalence of about 2%-3% in the United States – the prevalence of fibromyalgia increases with age.

Signs and Symptoms

The characteristic symptoms and signs of fibromyalgia often include:

• Generalized muscle and joint pain (myalgia, arthralgia)
• Numbness & tingling sensations (paresthesia)
• Fatigue & abnormal sleep
• Cognitive & psychiatric symptoms
• Headache

Psychiatric and cognitive symptoms typically include brain fog, depression, and anxiety.  Patients often have multiple tender points over the soft tissues on physical examination but no evidence of joint or muscle inflammation.  The presence of a tender point on the exam is not required for your doctor to make the diagnosis.

The disease often coexists with functional somatic disorders, including irritable bowel syndrome, chronic headache, and psychiatric disorders.  Patients may also have concomitant inflammatory or non-inflammatory musculoskeletal pain such as osteoarthritis, rheumatoid arthritis, and systemic lupus erythematosus.  This can make the diagnosis more difficult as symptoms often overlap.

Diagnosis

The diagnosis of fibromyalgia is suggested based on symptoms, history, and physical examination.  Laboratory tests are typically obtained to rule out other underlying disorders that can produce similar symptoms.  Doctors need to order laboratory tests judiciously, as patients with fibromyalgia frequently undergo multiple unnecessary tests that are costly and time-consuming.

Commonly ordered blood tests include a CMP (comprehensive metabolic panel), CBC (complete blood cell count), and thyroid function tests (TSH, free T4).  Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are typically obtained to evaluate systemic inflammation, which often occurs with inflammatory forms of arthritis.  Your doctor may order a creatine kinase test if they suspect underlying inflammatory muscle disease (myositis).

Occasionally, your doctor will order additional studies to evaluate for associated conditions – for example, patients with fatigue and impaired sleep may benefit from undergoing a sleep study to assess sleep apnea or restless leg syndrome.

Fibromyalgia Medication and Treatment

The treatment of fibromyalgia includes patient education, lifestyle measures, and pharmacologic therapy.  Your doctor will typically inform you that fibromyalgia is related to increased sensitivity to nerve pain and that the exact cause of the condition has not been identified.

Lifestyle changes often include the incorporation of exercise and physical activity, improving pain levels, and function.  Low-impact physical activity such as walking, biking, or swimming is preferred as high-impact activities may exacerbate pain.

Certain medications are beneficial in the treatment of fibromyalgia.  These typically include

• Elavil (amitriptyline)
• Cymbalta (duloxetine)
• Savella (milnacipran)
• Lyrica (pregabalin)

Medications are typically started at low doses and slowly up-titrated to achieve symptom control and reduce side effects.  The most common first-line therapy is low-dose Elavil before bedtime.  Patients with muscle spasms may also benefit from muscle relaxers, such as Flexeril (cyclobenzaprine).  Elderly patients should avoid tricyclics, such as Elavil, due to the risk of causing confusion and increasing falls.

References

1. Clauw DJ. Fibromyalgia: a clinical review. JAMA 2014; 311:1547. - https://jamanetwork.com/journals/jama/article-abstract/1860480
2. Jones GT, Atzeni F, Beasley M, et al. The prevalence of fibromyalgia in the general population: a comparison of the American College of Rheumatology 1990, 2010, and modified 2010 classification criteria. Arthritis Rheumatol 2015; 67:568. - https://www.ncbi.nlm.nih.gov/pubmed/25323744