Fibromyalgia Diagnosis and Characteristics

Core Clinical Features

• The American College of Rheumatology recommends suspecting fibromyalgia in patients with chronic widespread pain lasting at least 3 months, accompanied by fatigue, sleep disturbances, and cognitive dysfunction, particularly in women aged 30-60 years 1
• Chronic pain is present in all four body quadrants for a minimum of 3 months, characterized by hyperalgesia and allodynia 2, 3
• Fatigue that is disproportionate to activity level, non-restorative sleep, and cognitive dysfunction are associated symptoms that strengthen suspicion of fibromyalgia 1
• Mood disturbances, including anxiety and depression, are common in fibromyalgia patients 2

Demographic and Clinical Context

• The prevalence of fibromyalgia is approximately 2% in the general population, with a higher prevalence in women and increasing with age 1

Differential Diagnosis and Comorbidities

• Chronic fatigue syndrome may coexist or present similarly to fibromyalgia 2
• Post-Lyme disease syndrome can present with multiple tender points and widespread pain, fulfilling fibromyalgia criteria 4

Functional Impact Assessment

• The Fibromyalgia Impact Questionnaire (FIQ) can be used to measure functional impairment and impact on daily activities, assessing pain, fatigue, sleep quality, and daily functioning as key outcome domains 1

Diagnostic Considerations

• Diagnosis of fibromyalgia often takes over 2 years, with an average of 3.7 consultations with different physicians, leading to high healthcare utilization 1

Diagnostic Approach to Fibromyalgia

Diagnostic Criteria

• The American College of Rheumatology (ACR) criteria are most commonly used in clinical practice, focusing on widespread pain and associated symptoms rather than specific laboratory or imaging findings 5, 6

Laboratory Tests

• Basic laboratory screening, including erythrocyte sedimentation rate (ESR), is used to exclude inflammatory or endocrine diseases 5
• C-reactive protein (CRP) and thyroid function tests are also part of the basic laboratory screening 7
• Creatine kinase and vitamin D levels are included in the laboratory tests to rule out other conditions 7, 6

Functional Assessment

• The Fibromyalgia Impact Questionnaire (FIQ) is used to measure function and assess the impact of fibromyalgia on daily activities 6, 8
• The Visual Analogue Scale (VAS) is used to assess pain intensity in patients with fibromyalgia 6, 8

Differential Diagnosis

• Chronic fatigue syndrome and migraine are considered as overlapping conditions that may coexist with fibromyalgia 6

Psychosocial Aspects

• Addressing the psychosocial aspects of fibromyalgia is crucial, as the condition often has a significant impact on the patient's quality of life 7, 9

Diagnostic Criteria for Fibromyalgia: Tender Points

Introduction to Diagnostic Criteria

• The American College of Rheumatology recommends diagnosing fibromyalgia based on widespread pain for at least 3 months and pain upon digital palpation in at least 11 of 18 specific tender points 10, 11

Location of Tender Points

• Tender points are examined bilaterally (9 pairs) in specific anatomical locations, including the occiput, cervical spine, trapezius, supraspinatus, second rib, lateral epicondyle, gluteus, greater trochanter, and knee 10, 11

Examination Technique

• Approximately 4 kg of pressure should be applied during the examination, sufficient to blanch the examiner's fingernail bed 10, 11
• A tender point is considered positive when the patient reports pain (not just sensitivity) upon digital palpation 10, 11

Diagnostic Considerations

• Establishing a positive diagnosis and appropriate management can significantly reduce healthcare utilization 10, 11
• The Fibromyalgia Impact Questionnaire (FIQ) is used to measure functional impact in daily activities, pain, fatigue, sleep, and functioning 12

Diagnostic Workup for Fibromyalgia

Clinical Assessment

• The diagnostic workup for fibromyalgia is primarily clinical, requiring documentation of chronic widespread pain for at least 3 months plus comprehensive assessment of associated symptoms, followed by targeted laboratory testing to exclude mimicking conditions—not to confirm fibromyalgia itself, as recommended by the Annals of the Rheumatic Diseases 13, 14
• Environmental triggers such as alcohol, sleep deprivation, emotional stress, large meals, caffeine, and exercise should be specifically inquired about as potential precipitants, according to Circulation 15