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Presentation and Diagnosis of Fibromyalgia

Larry Culpepper, MD, MPH

Department of Family Medicine, Boston University School of Medicine, Boston Medical Center, Boston, Massachusetts

Fibromyalgia has a complex symptom presentation that includes widespread pain and usually sleep dysfunction/fatigue and depression.1 Patients with fibromyalgia often present in primary care settings, but their symptoms are frequently misdiagnosed or remain undiagnosed.2 By the time a patient is diagnosed, the symptoms typically have been present for some time and have had a severe impact on the quality of life of the patient and his or her family. After 20 years, new diagnostic criteria3 for fibromyalgia have been proposed that are more practical and less time-consuming to use in primary care settings than the previous classification criteria (AV 1AV 1).1

Clinical Presentation

Pain. Pain associated with fibromyalgia is widespread and diffuse, often muscular or musculoskeletal in origin, and is usually characterized as a generalized, deep, aching pain that has been present for years. Both the chronicity and the widespread nature of the pain must be confirmed; pain should be present for at least 3 months on both sides of the body and both above and below the waist.1 Pain may fluctuate over the course of the day and can be exacerbated by external factors.

Onset of pain symptoms may be gradual and difficult to detect. Patients might complain of lower back pain during one visit and headaches during another. Patients often have reconciled themselves to living with the pain and may only mention pain in certain areas, perhaps because they have not received effective treatment in the past.2 In fact, patients themselves may not recognize the pain as being widespread, and only through exploring the patient’s history do clinicians find that apparently unrelated pain complaints might be associated with fibromyalgia.

Sleep dysfunction. About 95% of patients with fibromyalgia experience sleep problems.4 These individuals characteristically sleep for a couple of hours, wake up, go back to sleep around 3:00 or 4:00 am, and wake up exhausted. Probably related to this nonrestorative sleep are the frequent complaints of significant fatigue, which can affect the patient’s ability to function at home, with child care, at work, and in social settings.

Depression. Not all patients with fibromyalgia will have a comorbid mood disorder; some may experience sadness due to chronic pain and fatigue. However, the lifetime rate of major depression in patients with fibromyalgia ranges from approximately 60% to 85%.2 When a mood disorder does co-occur with fibromyalgia, both disorders will require effective treatment in order to have a positive outcome for either one.5

Other symptoms. Patients with fibromyalgia may report having chronic headaches that are difficult to diagnose as tension or migraine headaches and that frequently have elements of both.2 Other frequent somatic symptoms to watch for include irritable bowel or bladder symptoms, temporomandibular joint pain, cognitive impairment (sometimes called "fibrofog"), and hypersensitivity to bright lights, loud sounds, or sudden disturbances.6,7

Common comorbidities. Although fibromyalgia is often mistaken for other disorders, it can present with other conditions as well. Common comorbidities include chronic fatigue syndrome, IBS, anxiety disorders, minor or major depression, rheumatoid arthritis, and lupus.8 Co-occurring TMJ syndrome, with teeth grinding and pain, may be associated with sleep difficulties and require specific treatment.9 And, opioid addiction due to previous misdiagnosis or attempted pain management is also a possible comorbidity.10

Precipitating factors. Patients may cite factors that they believe precipitated the onset of fibromyalgia symptoms, including psychological trauma (eg, a major disruption in their life or the loss of someone close or a job), physical trauma (eg, from a car wreck or a fall), or an illness (eg, pneumonia, a persistent flu episode, or Lyme disease). However, such associations are made with hindsight, and instead, those factors may have simply drawn attention to the fibromyalgia symptoms. For example, psychological trauma or a severe car accident might decrease an individual’s ability to function with the chronic pain that he or she was previously able to cope with.

More

Clinically, identifying causes of fibromyalgia with patients is not necessary or useful. Clinicians can acknowledge the importance that patients attach to any precipitating factors, but should not attempt to change the patient’s impression. A good response might be, "Well, that certainly could contribute to your worsening of symptoms," then switch the focus to moving forward with the diagnostic process and choosing effective therapy.

Differential Diagnosis

Several types of disorders can mimic fibromyalgia. Depending on individual patients’ presenting symptoms, clinicians may have to rule out endocrine disturbances, neurologic disorders, musculoskeletal diseases, infectious conditions, and psychiatric disorders (AV 2AV 2).

Adverse reactions to medications, such as myalgias associated with statin therapy for hyperlipidemia, particularly with high-dose statins, may also appear to be fibromyalgia. Before making a diagnosis, clinicians should determine whether painful symptoms developed after the initiation or dose increase of statin therapy. If a relationship seems to exist between statin therapy and widespread pain, a cessation of statin therapy or reduction of dose can be implemented for a few weeks to determine whether the pain symptoms resolve. Aromatase inhibitors and anticonvulsants may also cause pain symptoms. Ultimately, clinicians should always take a careful drug history when considering a diagnosis of fibromyalgia.

Assessing Patients for Pain

Since 1990, the ACR criteria for fibromyalgia1 have required a physical tender point examination, with at least 11 of 18 points being tender, to confirm widespread pain and to make a definitive diagnosis. However, concern exists that these criteria may be too rigid, and many patients with fibromyalgia may not meet the full diagnostic criteria. Additionally, many primary care clinicians are either unfamiliar with or cannot complete a full 18-point exam, possibly because of time constraints.

Therefore, the ACR proposed new diagnostic criteria to better account for the varying presentations of the disorder and to bypass the cumbersome tender point examination (AV 3AV 3).3 Instead, clinicians can use the WPI to assess pain locations and use the SS scale to evaluate fatigue, nonrestorative sleep, and cognitive impairment, as well as somatic symptoms. This new set of criteria has correctly identified nearly 90% of patients with fibromyalgia.3

Summary

Widespread pain is the hallmark symptom of fibromyalgia, and to correctly diagnose the disorder, clinicians may need to be persistent in assessing patients’ chronic pain. This includes being aware of the complex nature and presentation of fibromyalgia, such as co-occurring sleep disturbances, mood disorders, medical conditions, and other symptoms. Taking a thorough medical history, evaluating all medications the patient is taking, and using standardized assessments like the WPI and the SS scale will help in making a definitive and accurate diagnosis of fibromyalgia.

For Clinical Use

  • Assess patients who present with chronic pain for fibromyalgia
  • Perform differential diagnoses according to patients’ constellation of symptoms
  • Confirm that pain is widespread and chronic, and use the ACR criteria to diagnose fibromyalgia
  • Identify and treat comorbid conditions

Abbreviations

ACR = American College of Rheumatology, HCV = hepatitis C virus, HIV = human immunodeficiency virus, IBS = irritable bowel syndrome, SS = Symptom Severity, TMJ = temporomandibular joint, WPI = Widespread Pain Index

References

  1. Wolfe F, Smythe HA, Yunus MB, et al. The American College of Rheumatology 1990 Criteria for the Classification of Fibromyalgia. Report of the Multicenter Criteria Committee. Arthritis Rheum. 1990;33(1):160–172.
  2. Arnold LM, Clauw DJ, McCarberg BH, et al. Improving the recognition and diagnosis of fibromyalgia. Mayo Clin Proc. 2011;86(5):457–468.
  3. Wolfe F, Clauw DJ, Fitzcharles MA, et al. The American College of Rheumatology preliminary diagnostic criteria for fibromyalgia and measurement of symptom severity. Arthritis Care Res (Hoboken). 2010;62(5):600–610.
  4. Bigatti SM, Hernandez AM, Cronan TA, et al. Sleep disturbances in fibromyalgia syndrome: relationship to pain and depression. Arthritis Rheum. 2008;59(7):961–967.
  5. Arnold LM. Management of fibromyalgia and comorbid psychiatric disorders. J Clin Psychiatry. 2008;69(suppl 2):14–19.
  6. Glass JM. Fibromyalgia and cognition. J Clin Psychiatry. 2008;69(suppl 2):20–24.
  7. Wilbarger JL, Cook DB. Multisensory hypersensitivity in women with fibromyalgia: implications for well being and intervention. Arch Phys Med Rehabil. 2011;92(4):653–656.
  8. Weir PT, Harlan GA, Nkoy FL, et al. The incidence of fibromyalgia and its associated comorbidities: a population-based retrospective cohort study based on International Classification of Diseases, 9th Revision codes. J Clin Rheumatol. 2006;12(3):124–128.
  9. Hoffman RG, Kotchen JM, Kotchen TA, et al. Temporomandibular disorders and associated clinical comorbidities. Clin J Pain. 2011;27(3):268–274.
  10. Fleming MF, Balousek SL, Klessig CL, et al. Substance use disorders in a primary care sample receiving daily opioid therapy. J Pain. 2007;8(7):573–582.