How should I initially manage a patient over 50 years old with new‑onset headache, scalp tenderness, jaw claudication and visual disturbances suggestive of giant cell arteritis?

Initial Management of Suspected Giant Cell Arteritis

Start high-dose oral prednisone 40–60 mg daily immediately upon clinical suspicion—do not wait for temporal artery biopsy or imaging results, because untreated GCA carries a 14–50% risk of permanent, irreversible vision loss. 1, 2

Immediate Pharmacologic Intervention

For Patients WITH Visual Symptoms or Threatened Vision Loss

• Administer intravenous methylprednisolone 500–1000 mg daily for 3 consecutive days, then transition to high-dose oral prednisone 40–60 mg daily 1, 2, 3
• This aggressive approach is critical because anterior ischemic optic neuropathy can progress to bilateral blindness within hours to days 3

For Patients WITHOUT Visual Symptoms

• Start oral prednisone 40–60 mg daily (or 1 mg/kg/day, maximum 60 mg) immediately 1, 2, 4
• Avoid routine IV pulse glucocorticoids in this population due to increased infection risk in elderly patients 1, 3

Adjunctive Therapy at Diagnosis

• Add tocilizumab (IL-6 receptor antagonist) at the time of diagnosis for all GCA patients to reduce cumulative glucocorticoid exposure and prevent disease relapses 1, 3
• Prescribe low-dose aspirin 75–150 mg daily to reduce cardiovascular and cerebrovascular ischemic events 2, 3

Diagnostic Confirmation (Performed Concurrently, Not Before Treatment)

Temporal Artery Biopsy

• Obtain a ≥1 cm length specimen within 2 weeks of starting glucocorticoids to maximize diagnostic yield 1, 2
• Skip lesions occur in approximately 10% of cases, making shorter specimens prone to false-negative results 1, 2
• Histopathologic changes remain detectable for 1–2 weeks after glucocorticoid initiation, so biopsy can be performed after treatment starts 1, 2
• Initially perform unilateral biopsy; proceed to contralateral biopsy only if the first is negative and clinical suspicion remains high 1

Vascular Imaging

• Obtain baseline MR or CT angiography of the neck, chest, abdomen, and pelvis to evaluate large-vessel involvement and establish a reference for future monitoring 1, 3
• Temporal artery ultrasound showing a "halo sign" (circumferential wall thickening) has 88% sensitivity and 97% specificity when performed by experienced operators 2
• Consider imaging when biopsy is negative but clinical suspicion remains high 1, 2

Clinical Assessment Framework

High-Specificity Symptoms (Positive Likelihood Ratios)

• Jaw claudication (pain with chewing that resolves with rest): LR+ 4.90, present in ~50% of patients 2, 3, 4
• Temporal artery thickening on palpation: LR+ 4.70 2, 3
• Loss of temporal artery pulse: LR+ 3.25 2, 3
• Scalp tenderness: LR+ 3.14 2, 3, 4
• Limb claudication: LR+ 6.01, predicts severe ischemic complications 3

Common Presenting Features

• New-onset headache: present in 66–90% of biopsy-confirmed cases, often temporal in location 2, 4
• Visual disturbances: transient vision loss (amaurosis fugax), diplopia, or blurred vision occur in ~20% before permanent blindness 2, 3
• Constitutional symptoms: fever, weight loss ≥2 kg, fatigue, night sweats 2
• Polymyalgia rheumatica symptoms: proximal muscle pain and stiffness in shoulders and hips 4, 5

Physical Examination Priorities

• Palpate temporal arteries for thickening, tenderness, or absent pulse 2, 4
• Assess scalp tenderness with light pressure 2, 3
• Measure blood pressure in all four extremities to detect large-vessel involvement 1, 3
• Auscultate for bruits over axillary regions 3
• Perform comprehensive ophthalmologic evaluation in all patients with visual symptoms 3

Laboratory Evaluation

Inflammatory Markers

• ESR >100 mm/h: LR+ 3.11 2
• ESR <40 mm/h: LR– 0.18 (strongly argues against GCA) 2
• CRP <2.5 mg/dL: LR– 0.38 (makes GCA unlikely) 2
• Platelet count >400 × 10³/µL: LR+ 3.75 2
• Note: ESR and CRP are elevated in >95% of GCA cases at diagnosis, but rare cases (<5%) present with normal inflammatory markers 2, 4

Demographic Risk Factors

• Age >50 years is mandatory; GCA does not occur below this age 2, 4
• Peak incidence at 70–75 years; age >70 increases pre-test probability (LR– 0.48 when absent) 2
• Female predominance (2–3:1 ratio) 2
• Higher prevalence in Northern European ancestry 2, 4

Critical Pitfalls to Avoid

• Never delay glucocorticoid initiation while awaiting biopsy or imaging—irreversible vision loss can occur within hours 1, 2, 3
• Never obtain biopsy specimens <1 cm in length due to skip lesions causing false-negatives 1, 2
• Never start with moderate-dose glucocorticoids (~30 mg daily) as initial therapy; evidence for lower doses is low quality and vision loss risk is high 3
• Never use alternate-day glucocorticoid dosing; daily dosing achieves higher remission rates 3
• Do not rely solely on ACR 1990 classification criteria for bedside diagnosis—they are intended for research classification, not clinical decision-making 2

Glucocorticoid Tapering Strategy

• Maintain initial high dose (40–60 mg daily) for 1 month before beginning taper 1, 3
• Taper to 15–20 mg/day by months 2–3 3
• Target ≤5 mg/day after 12 months if disease is controlled 1, 3
• Guide tapering by clinical symptoms and inflammatory markers (ESR/CRP), not by fixed schedules 1, 3
• Treatment typically requires 1–2 years to avoid recurrence 2

Monitoring and Follow-Up

• Assess clinical symptoms (headache, jaw claudication, visual changes) and inflammatory markers (ESR, CRP) at each visit to guide treatment adjustments 1, 4
• Monitor for glucocorticoid-related adverse effects throughout therapy 1, 4
• Initiate bone protection therapy (calcium, vitamin D, bisphosphonates) for all patients unless contraindicated 2
• Perform periodic vascular imaging in patients with known large-vessel involvement to assess for aneurysms and stenoses 1, 3

Management of Disease Relapse

• Escalate glucocorticoid dose if relapse occurs 2
• Add or change non-glucocorticoid immunosuppressive agent (e.g., switch from methotrexate to tocilizumab or add abatacept) if relapse occurs despite adequate glucocorticoid therapy 2
• Consider methotrexate as a steroid-sparing agent when tocilizumab is unavailable or contraindicated 1, 2

Treatment Target Beyond Symptom Control

Prevention of tissue ischemia and vascular damage is a specific treatment target, not just symptom resolution 1. This includes preventing both GCA-related complications (aortic aneurysms, vision loss, stroke) and macrovascular/microvascular damage from long-term glucocorticoid therapy 1. Importantly, progression of vascular damage—particularly aortic aneurysms—may occur even in patients in persistent clinical remission, requiring ongoing surveillance 1.