What are the signs and treatment of giant cell arteritis?

Giant Cell Arteritis: Signs and Treatment

Clinical Signs and Symptoms

Giant cell arteritis presents with a constellation of cranial, systemic, and vascular manifestations that require immediate recognition to prevent irreversible vision loss. 1, 2

Cranial Manifestations

• New-onset headache is the most common presenting symptom 1
• Jaw claudication (pain with chewing) has a positive likelihood ratio of 4.90, making it one of the strongest clinical predictors 1
• Scalp tenderness occurs frequently and has a positive LR of 3.14 1
• Temporal artery abnormalities including:
  • Thickening (positive LR 4.70) 1
  • Tenderness (positive LR 3.14) 1
  • Loss of pulse (positive LR 3.25) 1

Visual Manifestations

• Vision loss occurs in 14-18% of patients and represents the most feared complication 1, 2
• Transient visual symptoms including amaurosis fugax (fleeting blindness) may herald permanent vision loss 3
• Diplopia (double vision) can occur from cranial nerve involvement 3
• Vision loss is typically irreversible unless treatment is initiated within days 4, 3

Systemic Manifestations

• Polymyalgia rheumatica symptoms (proximal muscle pain and stiffness) 1
• Constitutional symptoms including fever, weight loss, and fatigue 1
• Limb claudication has the highest positive LR of 6.01 1

Rare Ischemic Complications

• Stroke from large vessel involvement 2, 5
• Cranial nerve palsies 2
• Scalp necrosis from severe ischemia 2, 6
• Large-vessel aneurysms and stenoses 2

Laboratory Findings

• ESR >100 mm/h has a positive LR of 3.11 1
• ESR >40 mm/h is present in >95% of cases; absence has a negative LR of 0.18 1, 7
• CRP ≥2.5 mg/dL is elevated in most cases; absence has a negative LR of 0.38 1
• Platelet count >400 × 10³/μL has a positive LR of 3.75 1, 2

Important caveat: No single clinical or laboratory feature is sufficient alone to confirm or exclude GCA—combinations of findings must guide diagnostic decisions. 1

Treatment Approach

Immediate Management

All patients with suspected GCA must receive empiric high-dose glucocorticoids immediately, even before diagnostic confirmation, because untreated disease leads to bilateral blindness in up to 50% of cases within days. 3, 8

Initial Glucocorticoid Therapy

• High-dose oral prednisone 40-60 mg daily is the cornerstone of initial treatment 2, 7
• For patients with vision loss or imminent vision loss, consider intravenous methylprednisolone before transitioning to oral prednisone 1 mg/kg/day 3
• Do not delay treatment to obtain temporal artery biopsy—biopsy remains diagnostic for several days after starting steroids 7

Adjunctive Antiplatelet Therapy

• Low-dose aspirin 75-150 mg daily should be given to all GCA patients to reduce cardiovascular and cerebrovascular events 7, 3

Steroid-Sparing and Adjunctive Agents

Tocilizumab (FDA-approved for GCA) should be considered as adjunctive therapy to reduce glucocorticoid requirements and flare rates. 7, 9

• Tocilizumab has demonstrated efficacy in reducing both glucocorticoid burden and disease flares 7, 9
• Methotrexate may be considered as an adjunct in patients at high risk of relapse 8

Monitoring and Follow-up

• Clinical monitoring with ESR and CRP should guide treatment decisions and steroid tapering 7
• Prolonged treatment is typically required with high rates of relapse during tapering 8
• Monitor for glucocorticoid-related adverse effects given the extended treatment duration 8
• Periodic imaging (MRI or CT) may be necessary for patients with known large-vessel involvement to assess complications 7

Critical Pitfalls to Avoid

• Never withhold treatment while awaiting biopsy results—vision loss can occur within hours to days 3
• Do not be falsely reassured by normal ESR/CRP—approximately 5% of GCA patients have normal inflammatory markers 7
• Monitor closely during steroid tapering—late recurrence of visual loss can occur during dose reduction 3
• Recognize that established blindness is permanent—the window for vision salvage is extremely narrow 4, 3