Polymyalgia rheumatica

Background

• Chronic inflammatory condition
• Primarily affects elderly
  • Almost exclusively in those over the age of 50, peak incidence occurs between ages 70-80

Clinical Features

• Onset abrupt or subacute (weeks-months)
• Proximal myalgia primarily involving hips, shoulders, and neck
• Morning stiffness
• Giant cell arteritis develops in approximately 15% of patients with PMR
• +/- constitutional symptoms (fatigue/malaise, low-grade fever, anorexia)
• +/- anemia
• Rheumatoid arthritis-like symptoms (joint pain/swelling, degenerative changes) in 30% of patients

Differential Diagnosis

Myalgia

• Infection:
  • Viral infection (e.g. Influenza)
  • Bacterial infection
  • Spirochete infection (E.g. Dengue fever; Trichinella)
• Drugs:
  • Statins
  • Bisphosphonates
  • Corticosteroids
  • Ciprofloxacin
  • Clofibrate
  • Colchicine
  • Chloroquine
  • Emetine
  • Aminocaproic acid
  • Zidovudine
  • Bretylium
  • Penicillamine
  • Drugs causing hypokalemia
• Metabolic disorders:
  • Vitamin D deficiency
  • Mitochondrial myopathy
  • Scurvy
  • Osteomalacia
• Fibromyalgia
• Endocrine:
  • Hypothyroidism
  • Hyperthyroidism
  • Cushing’s syndrome
  • Adrenal insufficiency
  • Hyperparathyroidism
• Polymyalgia rheumatica
• Rhabdomyolysis
• Myositis
  • Polymyositis
  • Dermatomyositis
  • Myositis (peds)
• Systemic lupus erythematosus
• Rheumatoid arthritis
• Inclusion body myositis
• Sarcoidosis
• Scleroderma
• Sjögren’s syndrome
• Psychiatric (e.g. somatic manifestations of depression)
• Domestic abuse
• Crush injury
• Lyme disease
• Ehlers-Danlos syndrome(hypermobility syndrome)
• HIV myopathy
• Hypophosphatemia
• Hypokalemia
• Hypothermia
• Prolonged immobility
• Strenuous exercise (overuse) or heat stroke
• Seizure
• Severe volume contraction
• Alcoholism
• Muscular dystrophy
  • Duchenne
  • Becker
  • Limb-girdle
  • Facioscapulohumeral
  • Myotonic dystrophy
  • Myotonia congenita
• Compartment syndrome; Muscle infarction
• Neuropathic
• Chronic fatigue syndrome
• Vasculitis
• Sarcocystosis
• Spinal stenosis
• Diabetic lumbosacral plexopathy

Evaluation

• Clinical diagnosis
• Evaluate for alternate diagnoses

Management

• Low-dose Corticosteroids typically produce rapid response
  • Example regimen:
    • Prednisone 15 mg PO QD for 2-4 weeks
    • Needs to start a year-long taper after the first month, so write enough for them to get in with PCP.
• Avoid NSAIDs if history of or concern for GCA due to risk of renal injury

Disposition

• Discharge

See Also

• Giant cell arteritis