Recommended Investigations for Fibromyalgia Diagnosis
Fibromyalgia diagnosis requires a comprehensive assessment of pain, function, and psychosocial context, with laboratory tests primarily used to exclude other conditions rather than to confirm fibromyalgia. 1
Diagnostic Criteria
- Fibromyalgia is diagnosed using established criteria that focus on widespread pain and associated symptoms rather than specific laboratory or imaging findings 2
- The American College of Rheumatology (ACR) criteria are most commonly used in clinical practice 1
Recommended Investigations
Initial Assessment
- Complete medical history including medication review 4
- Comprehensive physical examination 4
- Assessment of pain distribution (must be present in all four quadrants of the body for at least 3 months) 3, 2
- Evaluation of associated symptoms: fatigue, sleep disturbance, cognitive dysfunction, mood disorders 5
Laboratory Tests
- Basic laboratory screening to exclude inflammatory or endocrine diseases 4:
- Complete blood count (CBC)
- Erythrocyte sedimentation rate (ESR)
- C-reactive protein (CRP)
- Thyroid function tests
- Creatine kinase
- Vitamin D levels
Screening Tools
- Fibromyalgia Rapid Screening Tool can be helpful for patients with diffuse chronic pain 5
- Fibromyalgia Survey Questionnaire (FSQ) can assist physicians in diagnosis 4
Functional Assessment
- Assessment of limitations in daily functioning 4
- Evaluation using the Fibromyalgia Impact Questionnaire (FIQ) to measure function 1
- Visual Analogue Scale (VAS) to assess pain intensity 1
Differential Diagnosis
- Screening for other functional somatic symptoms and mental disorders 4
- Exclusion of systemic and rheumatic diseases through history, examination, and laboratory investigations 2
- Consideration of overlapping conditions 2:
- Irritable bowel syndrome
- Chronic fatigue syndrome
- Migraine
- Primary mood disorders
When to Refer
- Referral to specialists only in case of suspected somatic diseases 4
- Rheumatologist consultation may be needed to exclude difficult-to-diagnose inflammatory rheumatic diseases 4
- Mental health specialist referral when significant psychiatric disorders are present 4
Common Pitfalls to Avoid
- Relying solely on tender points for diagnosis - the ACR 2010 criteria moved away from this approach 4
- Excessive laboratory testing or imaging studies that don't contribute to diagnosis 5
- Failing to recognize that fibromyalgia often coexists with other rheumatologic conditions 5
- Not addressing the psychosocial aspects of the condition 1