Rosen & Barkin's 5-Minute Emergency Medicine Consult (273 page)

CODES

• 610.1 Diffuse cystic mastopathy
  
• 610.2 Fibroadenosis of breast
  
• 610.9 Benign mammary dysplasia, unspecified
  

BASICS

• Nonarticular, noninflammatory form of muscular and joint pain more common in females:
  
  • Widespread pain from stimuli that do not normally cause pain (allodynia)
    
  • >11 diffuse tender points
    
  • Fatigue
    
  • Sleep disturbance
    
  • Muscle stiffness
    
  • Difficulties with attention, memory
    
  • Limited physical findings
    
• Not diagnosis of exclusion, may occur with other rheumatic diseases
  

• Mechanism:
  
  • Painful symptoms believed to result from greater activation of pronociceptive (pain-causing) system relative to antinociceptive (pain-dampening) system in brain and spinal cord.
    
• Abnormalities identified as possible mechanism:
  
  • Increased substance P (facilitates pronociception)
    
  • Decreased biogenic amines (NE, serotonin, dopamine), which facilitate antinociception
    
  • Decreased gray matter in brain
    
  • Genetics: 1/3 of patients with fibromyalgia have a close relative who is affected:
    
    • Candidate genes include 5-HT2A, serotonin transporter, D4 receptor, others
      
  • Like many complex diseases, psychological factors play a role, with high incidence of psychiatric disorders.
    
  • In genetically predisposed individuals, likely starts as initial insult from age, trauma, illness, inflammation, etc.
    
  • Hypothalamus–pituitary–adrenal axis stress-response dysfunction has been indicated to precede development of fibromyalgia
    

DIAGNOSIS

Widespread pain reported above the waist, below the waist, on the left side of the body, and on the right side of the body along with axial skeleton pain:

• Pain reported for >3 mo
  

• Generalized musculoskeletal pain and morning stiffness
  
• Weakness and fatigue
  
• Sleep disturbance
  
• Muscle spasms
  
• Persistent fatigue not relieved with rest (consider chronic fatigue syndrome)
  
• Numbness or tingling in the arms or legs
  
• Impaired concentration or memory
  
• Nausea, vomiting
  
• Abdominal pain or discomfort relieved with bowel movements (consider irritable bowel syndrome)
  
• Ear pain
  
• Sinus pressure (consider sinusitis)
  
• Jaw or face pain (consider TMJ disorder)
  
• Temple pain (consider temporal arteritis)
  
• Pelvic or bladder discomfort (consider interstitial cystitis)
  
• Tension or migraine headaches (consider causes of chronic headache)
  
• Irritation or itching at introitus (consider vulvodynia)
  

Exam findings usually limited

• History is key to diagnosis.
  
• In the ED, necessary only to distinguish between acute pain from trauma, injury, or new-onset medical conditions and chronic pain, which will require ongoing care and treatment.
  
• If a diagnosis of fibromyalgia is required, use classification criteria established by American College of Rheumatology (ACR) for fibromyalgia:
  
  • Widespread
    pain present for at least 3 mo defined as pain on both left and right side of body, above and below waist, and axial skeletal pain (cervical or anterior chest or thoracic spine or low back pain).
    
  • 11 of the 18 specific tender points on digital palpation with force of <4 kg/cm (amount of pressure required to blanch thumbnail) known as the Widespread Pain Index (WPI)
    
  • The 9
    paired
    (bilateral) tender points are located at the:
    
    • Occiput: Suboccipital muscle insertions
      
    • Low cervical: Anterior aspects of C5–C7 intertransverse spaces
      
    • Trapezius: Midpoint of upper border
      
    • Supraspinatus: Above medial border of scapular spine
      
    • 2nd rib: 2nd costochondral junction just lateral to the junctions on upper surfaces
      
    • Lateral epicondyle: ∼2 cm distal to epicondyles
      
    • Gluteal: Upper outer quadrant of buttocks
      
    • Greater trochanter: Posterior to trochanteric prominence
      
    • Knee: Medial fat pad proximal to joint line
      
  • OR diagnosis can be made with a WPI ≥7 and a Symptom Severity (SS) scale ≥5 OR WPI 3–6 and SS ≥9.
    
  • The SS scale (0–12) evaluates fatigue, waking unrefreshed, and cognitive symptoms
    
  • The 3 symptoms are rated on the following scale for level of severity over the past week:
    
    • 0 = no problem
      
    • 1 = slight or mild problems, generally intermittent
      
    • 2 = moderate, considerable problems, often present and/or at a moderate level
      
    • 3 = severe: Pervasive, continuous, life-disturbing problems
      
  • In addition, the SS scale rates somatic symptoms as follows:
    
    • 0 = no symptoms
      
    • 1 = few symptoms
      
    • 2 = moderate number of symptoms
      
    • 3 = great deal of symptoms
      
    • Somatic symptoms that might be considered: Muscle pain, irritable bowel syndrome, fatigue/tiredness, thinking or remembering problems, muscle weakness, headache, pain/cramps in the abdomen, numbness/tingling, dizziness, insomnia, depression, constipation, pain in the upper abdomen, nausea, nervousness, chest pain, blurred vision, fever, diarrhea, dry mouth, itching, wheezing, Raynaud phenomenon, hives/welts, ringing in ears, vomiting, heartburn, oral ulcers, loss of/change in taste, seizures, dry eyes, shortness of breath, loss of appetite, rash, sun sensitivity, hearing difficulties, easy bruising, hair loss, frequent urination, painful urination, and bladder spasms.
      

• Required only for evaluation of alternative diagnoses or acute pain:
  
  • CBC
    
  • Blood chemistries
    
  • ESR
    
  • Muscle enzymes
    
  • Thyroid function tests
    
  • Urinalysis
    
• No specific lab abnormalities are characteristic of fibromyalgia.
  

No specific radiographic abnormalities are characteristic.

Required only to evaluate causes of acute pain

• Myofascial pain syndrome (
  trigger points
  present, not
  tender points
  )
  
• Chronic fatigue syndrome
  
• Major depression
  
• Polymyalgia rheumatica
  
• Lyme disease
  
• Hypothyroidism
  
• Collagen vascular disease
  
• Electrolyte imbalance
  
• Myopathies (metabolic and drug induced)
  
• Osteomalacia
  
• Psychogenic rheumatism
  
• Eosinophilia–myalgia syndrome
  
• UTI
  
• Spondyloarthropathy
  
• Multiple chemical sensitivity
  
• Interstitial cystitis
  

TREATMENT

• Patient education and reassurance:
  
  • Emphasize that fibromyalgia is not life-threatening and does not reduce life expectancy.
    
  • Disorder is chronic but not crippling or deforming.
    
  • Goal is to manage pain and improve functional disability.
    
• Patients will require ongoing care and should be referred to a primary physician or pain specialist.
  
• Pharmacologic therapy:
  
  • Pharmacotherapy for improving pain, relaxing muscles, and improving sleep quality has been most successful with CNS agents such as pregabalin or gabapentin.
    
  • Opioids are not indicated for chronic pain and may actually worsen a patient’s long-term pain by acting as NDMA receptor agonists.
    
  • Combinations of medications (e.g., amitriptyline and fluoxetine or amitriptyline and cyclobenzaprine) may be more beneficial than either medication alone.
    
  • Tricyclic antidepressants (TCAs; amitriptyline, nortriptyline) likely superior to SSRIs.
    
  • Serotonin norepinephrine reuptake inhibitors (duloxetine, milnacipran) may be more effective than SSRIs and better tolerated than TCAs.
    
  • Tramadol is an adjunctive agent.
    
  • Benzodiazepines (clonazepam) are of no benefit other than their role in sleep disturbances.
    
  • NSAIDs and corticosteroids have not been shown to be effective.
    
  • Steroids or local anesthetic (lidocaine) injection into tender points is controversial:
    
    • No studies available to prove efficacy
      

• Acetaminophen: 650 mg PO q4h
  
• Amitriptyline: 25–50 mg PO at bedtime
  
• Cyclobenzaprine: 5–10 mg PO TID
  
• Duloxetine: 60 mg PO daily or BID
  
• Gabapentin: Start 300 mg PO TID, titrate upward beginning at 300 mg/d to max. of 1200 mg
  
• Milnacipran: Start at 12.5 mg/d, then titrate upward to max. of 50–100 mg PO BID
  
• Pregabalin: Start 50 mg PO TID, titrate upward to max. 450 mg/d PO in divided doses
  
• Tramadol: 300–400 mg/d PO