What is fibromyalgia?

Fibromyalgia: Definition, Diagnosis, and Management

Fibromyalgia is a chronic condition characterized by widespread musculoskeletal pain, fatigue, unrefreshing sleep, and cognitive issues that significantly impacts quality of life, with diagnosis requiring a history of generalized pain present for at least 3 months and specific symptom criteria. 1

Definition and Characteristics

Fibromyalgia presents as a complex syndrome with the following key features:

• Chronic widespread musculoskeletal pain as the defining feature
• Fatigue and unrefreshing sleep
• Cognitive difficulties (often called "fibro fog")
• Significant impact on quality of life and healthcare utilization (average cost >$2000 per patient per year) 1

The condition represents a central pain processing disorder rather than peripheral tissue damage or inflammation 2.

Diagnostic Criteria

According to the American College of Rheumatology (ACR), diagnosis requires:

• Traditional criteria (1990):

  • History of generalized pain present for at least 3 months
  • Pain upon digital pressure in at least 11 of 18 specific tender points
  • Pressure of approximately 4 kg 1

• Updated criteria (2010):

  • Less reliance on tender points
  • Inclusion of widespread pain index (WPI)
  • Symptom severity scale (SS) that captures cognitive difficulties
  • Less extensive pain requirements 3

Pathophysiology

Fibromyalgia involves several key mechanisms:

• Central sensitization: Heightened pain processing in the central nervous system 4, 2
• Impaired descending pain inhibition: Dysfunction in pain-dampening pathways 4
• Neurotransmitter abnormalities: Including:
  • Reduced levels of biogenic amines
  • Increased concentrations of excitatory neurotransmitters (substance P)
  • Dysregulation of the hypothalamic-pituitary-adrenal axis 5
• Genetic factors: Polymorphisms in serotoninergic, dopaminergic, and catecholaminergic systems 4
• Potential triggers: Infection, trauma, stress, and other pain conditions 4, 5

Management Approach

Non-Pharmacological Therapies (First-Line)

The American College of Rheumatology strongly recommends starting with non-pharmacological approaches:

• Exercise therapy (strongest evidence base):

  • Aerobic exercise and strength training
  • 2-3 sessions/week, 10-30 minutes per session
  • Start with low intensity and gradually increase 1

• Cognitive Behavioral Therapy (CBT):

  • Addresses pain catastrophizing
  • Improves coping strategies
  • Typically 8-12 weekly sessions 1

• Other beneficial approaches:

  • Heated pool treatment/hydrotherapy
  • Mindfulness-based stress reduction
  • Relaxation techniques
  • Meditative movement (yoga, tai chi, qigong)
  • Mediterranean-style diet 1

Pharmacological Therapies

First-line pharmacological options include:

• Pregabalin (75 mg twice daily):

  • FDA-approved for fibromyalgia
  • Effective for pain and sleep disorders
  • Clinical trials showed significant improvement in pain scores and patient global impression of change 1, 6

• Duloxetine:

  • FDA-approved for fibromyalgia
  • Particularly useful when comorbid with depression or anxiety
  • Common side effects include nausea, dry mouth, constipation, and somnolence 1, 7

• Milnacipran:

  • FDA-approved SNRI for fibromyalgia
  • Recommended especially with comorbid depression or anxiety 1

• Amitriptyline (10-25 mg at bedtime):

  • Effective for pain and sleep disorders
  • Use with caution in older adults 1

Medications Not Recommended

• NSAIDs: Lack of efficacy for fibromyalgia-specific pain 1
• Strong opioids: Not recommended due to potential for harm without clear benefit 1
• Corticosteroids: Not effective and potential for harm 1
• Cannabis: Not recommended as first-line due to limited and inconsistent evidence, lack of standardization, and potential for adverse effects 1

Special Considerations

• Pregnant patients: Focus on non-pharmacological approaches 1
• Elderly patients: Use lower initial medication doses with gradual titration 1
• Comorbid conditions: Address fibromyalgia symptoms separately while continuing treatment for other conditions 1

Monitoring and Follow-up

Regular monitoring is essential to:

• Assess adherence to exercise program
• Evaluate symptom improvement
• Determine need for additional interventions
• Adjust treatment plan as needed 1

Common Pitfalls to Avoid

1. Misdiagnosis: Ensure proper exclusion of other conditions that could explain symptoms
2. Over-reliance on medications: Remember that non-pharmacological approaches should be first-line
3. Ignoring psychological aspects: Address both physical and psychological components
4. Expecting quick results: Patient education about the chronic nature of the condition is essential
5. Using ineffective treatments: Avoid NSAIDs, opioids, and corticosteroids that lack efficacy for fibromyalgia