- Women account for more than 75-85% of Fibromyalgia patients (female gender RR 2-14)
- Peak Incidence: ages 20 to 60 years old
- Incidence increases with age
- Most common rheumatic cause of chronic diffuse pain
- Most common cause of Chronic Pain in women ages 20 to 55 years old
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Incidence
- Rheumatology patients: 15%
- Only Osteoarthritis is more common in rheumatology practice
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General medical patients: 5%
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General female population: 2-3%
- Increased central sensitivity to peripheral Sensation (as with other functional pain syndromes)
- Pain system dysfunction related to abnormalities in the forebrain
- Dysfunctional central nociceptive signal processing leading to hyperalgesia and Allodynia
- Imbalance between excitatory and inhibitory Neurotransmitters including within the insula
- See Fibromyalgia Rapid Screening Tool
- Chronic diffuse pain (100%)
- Predominant, core symptom
- Severe Fatigue (81%)
- Morning stiffness longer than 15 minutes (77%)
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Sleep Disorder (75%)
- Difficulty falling asleep, staying asleep or frequent awakenings
- Non-restorative sleep (alpha-delta sleep)
- Sleep Apnea
- Nocturnal Myoclonus
- Restless Leg Syndrome
- Atypical Paresthesias (63%)
- Anxiety (48%)
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Dry Mouth (36%)
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Recurrent Headaches (53%)
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Dysmenorrhea (41%)
- Past History of Major Depression (31%)
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Irritable Bowel Syndrome (30-70%)
- Urinary urgency (26%)
- Cold sensitivity or Raynaud's Phenomenon (17%)
- Cognitive impact ("Fibro Fog)
- Decreased concentration and attention
- Mental slowing
- Symptoms
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Exacerbating Factors
- Post-exertional increase in Muscle pain
- Emotional Stress or Abuse
- See Diagnosis below
- Diffuse soft tissue Tender Points
- Not associated with focal or generalized findings to suggest other rheumatologic cause
- Joint inflammation, swelling or deformity suggests alternative diagnosis
- However, Fibromyalgia may coexist with other Pain Disorders (see associated comorbid conditions below)
- Fibromyalgia is a clinical diagnosis and labs are not required in routine causes
- Labs are normal in isolated Fibromyalgia
- Labs are often obtained to evaluate specific prominent symptoms (e.g. Fatigue)
- Standard Evaluation
- Complete Blood Count (CBC, esp. Hemoglobin)
- Basic Metabolic Panel (e.g. Chem8)
- Thyroid Stimulating Hormone (TSH)
- Additional tests when indicated (non-specific tests, order judiciously, when rheumatologic features are present)
- Erythrocyte Sedimentation Rate (ESR)
- C-Reactive Protein (C-RP)
- Antinuclear Antibody (ANA)
- Rheumatoid Factor (RF)
- Creatinine Phosphokinase (CPK)
- Fibromyalgia specific testing
- FM/a Cytokine Array-based Test
- May be used to confirm Fibromyalgia Diagnosis
- Test Sensitivity: 93%
- Test Specificity: 89% (70% when patient has comorbid Rheumatologic Conditions)
- Positive Likelihood Ratio: 3.1
- Negative Likelihood Ratio: 0.1
- Straub (2021) Am Fam Physician 103(9): 566-7 [PubMed]
- Diagnosis
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General Criteria
- Fibromyalgia is a diagnosis of exclusion
- Widespread musculoskeletal pain ("I hurt all over")
- Regional: Each of 4 body quadrants involved
- Pain on left and right side of body
- Pain above and below waist
- Axial skeleton pain present
- Cervical Spine
- Anterior chest
- Thoracic Spine
- Low back
- Pain worse in the morning and at the end of the day
- Moderate to severe Fatigue or sleep problems
- Symptoms persist at least 3 months
- Diagnosis
-
Specific Diagnostic Tools
- Screening
- See Fibromyalgia Rapid Screening Tool
- AAPT Criteria 2019 (alternative to ACR Criteria, Test Sensitivity 74%)
- Six of 9 painful sites (head, each arm, each leg, chest, Abdomen, upper back, lower back/buttocks)
- Moderate to severe sleep problems or Fatigue
- Pain present for 3 months or more
- Arnold (2019) J Pain 20(6):611-628 +PMID: 30453109 [PubMed]
- ACR Criteria Updates 2016 (Test Sensitivity 78-80%)
- Generalized pain in 4 of 5 regions for at least 3 months
- Simplified Part 2 of the Symptom Severity Score
- Incorporates Widespread Pain Index, symptom severity and Fatigue, sleep and cognitive impacts
- ACR Criteria Updates 2010
- See ACR Fibromyalgia Diagnostic Criteria (ACRFDC)
- Widespread Pain Index replaced Tender Points
- ACR Original Criteria 1990
- See Tender Points (11 of 18 present)
- Replaced by newer ACR and AAPT Criteria
- References
- Salaffi (2020) Rheumatology 59(10): 3042-9 [PubMed]
- Associated Conditions
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Augmented Pain and Sensory Processing Disorders
- Associated Conditions
-
Common Comorbid Chronic Conditions
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