Description

• Chronic widespread physically debilitating pain syndrome:
  • Relapsing, diffuse, aching pain can be intermittent
  • Excessive generalized musculoskeletal tenderness
  • Tenderness exhibited as allodynia (nonpainful stimuli evoking pain), hyperpathia (painful stimuli evoking exaggerated and prolonged pain response), and hyperalgesia (extreme sensitivity to painful stimuli) (1)
  • Lasting ≥3 consecutive months
  • Commonly associated with symptoms such as:
    • Severe fatigue
    • Exercise intolerance and functional impairment of activities of daily living (ADLs)
    • Sleep disturbance (insomnia and nonrestorative sleep)
    • Cognitive dysfunction (especially issues with motivation, concentration, and organization)
    • Mood disorders (depression and anxiety)
• Synonym(s): Fibrositis; Psychogenic rheumatism

Epidemiology

• Predominant sex: Female > Male (~90% are females)
• Predominant age: 20–65 years

Prevalence
2–5% of adult US population (2)

Risk Factors

• Female gender
• Poor functional status
• Negative/stressful life events
• Low socioeconomic status

• Genetics:
  • Inheritance is unknown, but likely polygenic
  • High familial aggregation
  • Odds ratio may be as high as 8.5 for a 1st-degree relative of a familial proband
  • Commonly comorbid with mood or anxiety disorders in families
• Environmental:
  • Physical trauma or injury
  • Stressors (e.g., work, family, life events, and abuse)
  • Some studies report correlations to certain infections (e.g., Lyme disease and hepatitis C).

General Prevention

No specific prevention known

Etiology

• Combination of:
  • Abnormality in CNS pain processing
  • Genetic/Familial/Environmental factors
  • Mood or anxiety disorder
• Decrease in blood flow to the thalamus and caudate nucleus
• Afferent augmentation of peripheral nociceptive stimuli
• Alterations in neuroendocrine, neuromodulation, neurotransmitter, neurotransporter, biochemical, and neuroreceptor function/physiology (1)
• May be triggered or aggravated after a negative life event, physical injury, or illness

Commonly Associated Conditions

Arise in various parts of the body grouped as functional somatic syndromes, including (2):

• Irritable bowel syndrome, fatigue, morning stiffness, muscle weakness, headache, abdominal pain, dizziness, visceral organ dysfunction (noncardiac chest pain, heartburn, and palpitations), insomnia, depression, constipation, nausea, nervousness, blurred vision, fever, diarrhea, dry mouth, itching, wheezing, Raynaud phenomenon, hives, tinnitus, heartburn, oral ulcers, change in taste, seizures, dry eyes, dyspnea, loss of appetite, rash, sun sensitivity, hearing difficulties, easy bruising, hair loss, urinary urgency, bladder spasms, interstitial cystitis