Diagnosis of Fibromyalgia
Diagnose fibromyalgia using the American College of Rheumatology criteria: widespread pain lasting at least 3 months in all four body quadrants, accompanied by fatigue, sleep disturbances, and cognitive dysfunction—no laboratory tests or tender point examination are required for diagnosis. 1
Diagnostic Criteria
The American College of Rheumatology criteria are the standard for diagnosis, focusing on widespread pain for at least 3 months plus associated symptoms rather than tender point examination (the older 1990 criteria requiring 11 of 18 tender points are no longer necessary). 2
Widespread pain must be present in all four body quadrants for a minimum of 3 months, characterized by hyperalgesia (increased pain sensitivity) and allodynia (pain from normally non-painful stimuli). 1
Associated symptoms that strengthen the diagnosis include:
The Fibromyalgia Rapid Screening Tool can be used for initial screening in patients presenting with diffuse chronic pain. 3
Clinical Assessment
Comprehensive assessment must evaluate pain intensity (using 0-10 scale), functional limitations, sleep quality, fatigue severity, cognitive symptoms, and psychosocial factors including depression and anxiety. 2
The Fibromyalgia Impact Questionnaire (FIQ) measures functional impairment and impact on daily activities, assessing pain, fatigue, sleep quality, and daily functioning as key outcome domains. 1
Fibromyalgia represents abnormal central pain processing (central sensitization) rather than peripheral tissue damage—this is a critical concept for patient education. 2
Laboratory Testing to Exclude Other Conditions
Basic laboratory screening should include erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and thyroid function tests to exclude inflammatory or endocrine diseases. 1
Additional tests include creatine kinase and vitamin D levels to rule out other conditions. 1
There are no specific laboratory abnormalities in fibromyalgia—the diagnosis is entirely clinical. 4
Differential Diagnosis
Rule out systemic and rheumatic diseases through patient history, physical examination, and laboratory investigations—fibromyalgia is not a diagnosis of exclusion but requires active exclusion of organic diseases. 5
Consider overlapping conditions that may coexist:
Carefully evaluate for primary mood disturbances, as psychiatric disorders have higher prevalence in fibromyalgia patients. 5
Epidemiology and Clinical Context
Fibromyalgia affects approximately 2% of the general population, with higher prevalence in women (female-to-male ratio approximately 19:1 based on clinical trial data) and increasing prevalence with age. 1, 6
Diagnosis often takes over 2 years with an average of 3.7 consultations with different physicians, leading to high healthcare utilization. 1
Approximately 25% of fibromyalgia patients have comorbid major depressive disorder. 6
Treatment Approach After Diagnosis
Non-Pharmacological Management (First-Line)
Begin immediately with aerobic and strengthening exercise as the primary intervention—this has the strongest evidence (Level Ia, Grade A) for improving pain, function, and quality of life. 2
Initiate low-impact aerobic exercise (walking, swimming, cycling) at 20-30 minutes, 2-3 times weekly, gradually increasing to 30-60 minutes, 5 days weekly. 2
Add progressive resistance training 2-3 times weekly. 2
Heated pool therapy or hydrotherapy provides additional benefit and may improve exercise tolerance (Level IIa, Grade B). 7, 2
Cognitive behavioral therapy (CBT) is recommended for patients with depression, anxiety, or maladaptive coping strategies (Level Ia, Grade A). 2
Additional beneficial therapies include acupuncture (Level Ia, Grade A), meditative movement therapies (tai chi, yoga, qigong), and mindfulness-based stress reduction. 2
Pharmacological Management (Second-Line)
First-line medications (all Level Ia, Grade A evidence):
- Amitriptyline 10-25 mg at bedtime for patients with prominent sleep disturbance and pain; titrate by 10-25 mg weekly to 50-75 mg as tolerated 2
- Duloxetine 30 mg daily for 1 week, then increase to 60 mg daily for patients with pain plus depression or anxiety 2, 6
- Pregabalin 75 mg twice daily, titrate to 150 mg twice daily over 1 week for patients with predominant pain without mood symptoms 2, 8
Second-line medication:
- Tramadol for pain management when other medications are ineffective (Level Ib, Grade A) 7
Critical Medications to Avoid
Corticosteroids have no role in fibromyalgia treatment and should not be used. 7, 2
Strong opioids (morphine, oxycodone, hydrocodone) are not recommended as they lack demonstrated benefit and carry significant risks. 7, 2
NSAIDs (ibuprofen, naproxen) have limited to no benefit as monotherapy since fibromyalgia is not an inflammatory condition. 2
Monitoring and Reassessment
Evaluate treatment response every 4-8 weeks using pain scores (0-10 scale), functional status, and patient global impression of change. 2
Most treatments show modest effect sizes—expect 30-50% pain reduction rather than complete resolution. 2
Multicomponent therapy (combining exercise, CBT, and medication) may provide greater benefit than any single intervention. 2
Long-term management requires ongoing exercise maintenance and periodic reassessment of medication need. 2
Common Pitfalls to Avoid
Do not rely solely on pharmacological therapy without implementing exercise and behavioral approaches. 7
Do not fail to provide adequate patient education about the chronic nature of fibromyalgia and central sensitization as the underlying mechanism. 7, 2
Do not use tender point examination as a requirement for diagnosis—the newer ACR criteria do not require this. 2
Do not prescribe opioids or corticosteroids, as these have no demonstrated benefit and may cause harm. 2