Giant Cell Arteritis

1. See Also
   1. Headache
   2. Headache Evaluation
   3. Polymyalgia Rheumatica
2. Epidemiology
   1. Closely associated with Polymyalgia Rheumatica (50%)
   2. Prevalence: 133 per 100,000 over age 50 years
   3. Rarely occurs under age 50 years
   4. Average age of presentation: 72 years
3. Pathophysiology
   1. Inflammation of arteries originating from aortic arch
      1. Infiltration of arterial wall with inflammatory cells
      2. Localized to elastic laminae
         1. May extend to panarteritis
   2. Intima thickens results in lumen narrowing, Occlusion
4. Symptoms
   1. See Polymyalgia Rheumatica for rheumatologic symptoms
   2. Onset of symptoms
      1. Insidious over months or
      2. Sudden Onset
   3. Headache over temporal or occipital arteries (>50-70%)
   4. Visual symptoms
      1. Vision may be partially obscured
      2. Visual field cuts
      3. Diplopia
      4. Acute Vision Loss or Amaurosis Fugax
   5. Systemic symptoms
      1. Fever of Unknown Origin
      2. Malaise
      3. Weight loss
   6. Respiratory and other symptoms (10% of cases)
      1. Sore Throat
      2. Dry Cough
      3. Tongue Pain
      4. Pharyngitis
      5. Choking sensation
      6. Lower extremity Claudication
      7. Jaw Claudication (facial muscle pain with chewing)
         1. Highly specific for Temporal Arteritis
         2. May be atypical with tooth, sinus or Ear Pain
5. Signs
   1. See Polymyalgia Rheumatica for rheumatologic findings
   2. Tenderness over temporal or occipital arteries, scalp
   3. Temporal artery pulse reduction
   4. Eye exam to exclude other causes of vision change
      1. Visual Acuity
      2. Extraocular Movements
      3. Pupillary Light Reflex
         1. Observe for afferent pupillary defect
      4. Funduscopic Exam
6. Complications and Associated Conditions
   1. Sudden Vision Loss (Anterior Ischemic Optic Neuropathy)
      1. Occurs in 8-15% of Temporal Arteritis patients
      2. See Amaurosis Fugax
      3. Secondary to narrowing of arterial lumens
         1. Ophthalmic terminal branches
         2. Posterior ciliary arteries
      4. Visual deficit is permanent
   2. Polymyalgia Rheumatica (50%)
   3. Jaw Claudication (see above)
   4. Aortic Arch Syndrome
   5. Vertebrobasilar Artery thrombosis
   6. Myocardial Infarction
   7. Mesenteric Infarction
7. Associated Conditions
   1. Polymyalgia Rheumatica
8. Diagnosis
   1. Temporal Artery Biopsy
      1. Biopsy shows chronic inflammation
      2. Long biopsy specimens (>2 cm) are preferred
      3. Biopsy positive for 2 weeks after starting Prednisone
         1. Biopsy is best within 48 to 72 hours
   2. Findings most suggestive of Temporal Arteritis
      1. Beaded (nodular thrombus) temporal artery (+LR 4.6)
      2. Prominent temporal artery (+LR 4.3)
      3. Jaw Claudication (+LR 4.2)
      4. Diplopia (+LR 3.4)
      5. Temporal artery pulse absent (+LR 2.7)
      6. Temporal artery tender (+LR 2.6)
      7. Smetana (2002) JAMA 287:92-101
9. Labs
   1. Erythrocyte Sedimentation Rate (Westergren) Increased
      1. ESR exceeds 50 mm in 1 hour (Often >100 mm)
   2. C-Reactive Protein increased
   3. Nonspecific Lab findings
      1. Moderate Anemia
      2. Decreased Serum Albumin
      3. Mild hepatic dysfunction
10. Management: Prednisone
    1. Do not delay starting if high level of suspicion
       1. Biopsy within 2 weeks of starting Corticosteroids (best within first 48-72 hours)
    2. Starting Dose
       1. No visual symptoms
          1. Prednisone 40-60 mg PO qd for 4 months
       2. Visual symptoms
          1. Solumedrol 250 mg every 6 hours for 3-5 days
          2. Following solumedrol course, switch to oral Prednisone as above
    3. Efficacy
       1. Symptoms and Signs remit in approximately 1 month
       2. Targets: Vision change, fever, Headache, myalgias
       3. Do not use ESR normalization as a target
    4. Taper protocol
       1. Start tapering after 2-4 weeks on Prednisone
       2. Dose by decreasing dose 10% each week
       3. Anticipate low dose (10 mg) reached by 6 months
    5. Course
       1. Continue Prednisone 1-2 years if ocular complications
    6. Adjuvant medications
       1. Concurrent Methotrexate not recommended
    7. Prevention of complications from Prednisone
       1. See Corticosteroid Associated Osteoporosis
11. Course
    1. Self limited course over months to years with steroids
    2. Risk of permanent blindness if untreated
12. References
    1. Hellmann (2002) JAMA 287:2996-3000
    2. Loddenkemper (2004) Arch Neurol 61:1620-2
    3. Selvarani (2002) N Engl J Med 347:261-71
    4. Unwin (2006) Am Fam Physician 74:1547-58
    5. Weyand (2003) Ann Intern Med 139:505-15