How should a 55-year-old woman with suspected giant cell arteritis presenting with new temporal headache, scalp tenderness, jaw claudication, visual disturbances, and markedly elevated erythrocyte sedimentation rate and C‑reactive protein be managed?

Management of Suspected Giant Cell Arteritis

Start high-dose oral prednisone 40–60 mg daily immediately—do not wait for temporal artery biopsy or imaging results, because untreated GCA carries a 14–50% risk of permanent vision loss that can occur within hours to days. 1, 2

Immediate Pharmacologic Management

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
• This aggressive approach is critical because visual ischemia represents an ophthalmologic emergency 2

For Patients WITHOUT Visual Symptoms

• Start oral prednisone 40–60 mg daily immediately upon clinical suspicion 1, 2
• Do not use moderate-dose regimens (≈30 mg daily) as initial therapy—the evidence supporting lower doses is weak and the risk of vision loss is too high 2

Add Tocilizumab at Diagnosis

• Initiate tocilizumab (IL-6 receptor antagonist) 162 mg subcutaneously weekly or every other week at the time of diagnosis for all GCA patients 1, 3
• Tocilizumab is FDA-approved and should be started immediately rather than reserved for relapse management 1, 3
• In the pivotal trial, 56% of patients on tocilizumab weekly achieved sustained remission through 52 weeks versus only 14% on placebo with 26-week prednisone taper 3
• Tocilizumab reduces cumulative glucocorticoid exposure (median annual dose 1887 mg vs 3804 mg with placebo) and prevents disease relapses 1, 3

Add Low-Dose Aspirin

• Prescribe aspirin 75–150 mg daily to all GCA patients to reduce cardiovascular and cerebrovascular ischemic events 1, 2

Diagnostic Confirmation (Performed Urgently But Does NOT Delay Treatment)

Temporal Artery Biopsy (Gold Standard)

• Arrange temporal artery biopsy within 2 weeks of starting glucocorticoids 1
• The specimen must be at least 1 cm in length to minimize false-negative results from skip lesions (present in ≈10% of cases) 1, 2
• Histopathologic changes remain detectable for 1–2 weeks after glucocorticoid initiation 1
• Typical findings include arterial wall thickening, luminal narrowing, mononuclear inflammatory infiltrates in the media, and occasional multinucleated giant cells 1, 4
• Biopsy must be performed by an experienced surgeon and interpreted by an experienced pathologist 1

Vascular Imaging (Adjunctive/Alternative)

• Obtain baseline MR or CT angiography of the neck, chest, abdomen, and pelvis to evaluate large-vessel involvement 1, 2
• Temporal artery ultrasound showing "halo sign" (circumferential wall thickening) has 88% sensitivity and 97% specificity when performed by experienced operators 1
• Imaging within 24 hours of symptom onset lowers the incidence of permanent visual impairment 1

Clinical and Laboratory Features Supporting Diagnosis

High-Specificity Clinical Findings (Positive Likelihood Ratios)

• Jaw claudication: LR+ 4.90 (present in ≈50% of patients, most specific symptom) 1, 2
• Temporal artery thickening on palpation: LR+ 4.70 1, 2
• Absent temporal artery pulse: LR+ 3.25 1, 2
• Scalp tenderness: LR+ 3.14 1, 2
• Limb claudication: LR+ 6.01 (predicts severe ischemic complications) 2

Cardinal Symptoms

• New-onset headache (present in 66–90% of cases, often temporal location) 1
• Visual disturbances (transient vision loss/amaurosis fugax, diplopia, blurred vision—occur in 20% before permanent blindness) 1, 2
• Constitutional symptoms (fever, weight loss ≥2 kg, fatigue, night sweats) 1
• Polymyalgia rheumatica symptoms frequently coexist 1

Laboratory Markers

• ESR >100 mm/h: LR+ 3.11 1
• Absence of ESR >40 mm/h: LR– 0.18 (makes GCA unlikely) 1
• CRP ≥2.5 mg/dL: absence has LR– 0.38 1
• Platelet count >400 × 10³/µL: LR+ 3.75 1
• Elevated inflammatory markers are present in >95% of cases at diagnosis 1

Critical caveat: Normal ESR and CRP do not rule out GCA—if clinical suspicion is high based on symptoms, proceed with treatment and biopsy 5

Glucocorticoid Tapering Strategy

• Maintain initial high dose (40–60 mg daily) for 1 month 1, 2
• Taper to 15–20 mg/day by months 2–3 1, 2
• Target ≤5 mg/day after 12 months if disease is controlled 1, 2
• Guide tapering by clinical symptoms and inflammatory markers (ESR/CRP), not by fixed schedules 1, 2
• Do not use alternate-day dosing—daily dosing achieves higher remission rates 2
• Therapy typically requires 1–2 years to avoid recurrence 1

Monitoring and Follow-Up

Clinical Assessment

• Monitor for headache, visual symptoms, jaw claudication at each visit 1
• Perform comprehensive ophthalmologic evaluation in all patients with visual symptoms to assess for anterior ischemic optic neuropathy and cranial nerve palsies 2
• Check blood pressure differences between upper limbs and auscultate for bruits over axillary regions to detect large-vessel ischemia 2

Laboratory Monitoring

• Serial ESR and CRP measurements should guide treatment adjustments 1
• Do not measure IL-6 levels for monitoring 1

Imaging Follow-Up

• Periodic vascular imaging for patients with known large-vessel involvement to assess for aneurysms, stenoses, and stability of existing lesions 1
• Patients without large-vessel involvement may not require routine repeated imaging 1

Glucocorticoid Complication Prevention

• Initiate bone protection therapy (calcium, vitamin D, bisphosphonates) for all patients unless contraindicated 1
• Monitor for glucocorticoid-related adverse effects throughout therapy 1

Alternative Steroid-Sparing Agents

• Consider methotrexate as a steroid-sparing agent when tocilizumab is unavailable or contraindicated 1, 6
• Abatacept is reasonable as adjunctive therapy 1

Management of Disease Relapse

• Escalate glucocorticoid dose if relapse occurs 1
• Add or change non-glucocorticoid immunosuppressive agent (e.g., switch from methotrexate to tocilizumab or add abatacept) if relapse occurs despite adequate glucocorticoid therapy 1

Critical Pitfalls to Avoid

• Never delay glucocorticoid initiation while awaiting biopsy or imaging—irreversible vision loss can occur within hours to days 1, 2
• Never obtain biopsy specimens shorter than 1 cm—skip lesions cause false-negative results in ≈10% of cases 1, 2
• Never start with moderate-dose glucocorticoids (≈30 mg daily) as initial therapy—the risk of vision loss is too high 2
• Never use alternate-day glucocorticoid dosing—daily dosing is superior 2
• Never rely solely on normal inflammatory markers to exclude GCA—proceed with treatment and biopsy if clinical suspicion is high 5

Ischemic Complications to Recognize

• Vision loss (14–18% of untreated patients, up to 50% without therapy) 2
• Amaurosis fugax (transient vision loss—urgent warning sign in ≈20% before permanent blindness) 2
• Diplopia (from ischemia of extraocular muscles and cranial nerves) 2
• Stroke (from vertebral and carotid artery involvement) 2, 4
• Cranial nerve palsies (from ischemia of vasa nervorum) 2, 4
• Scalp necrosis (signals advanced disease with severe ischemia) 2, 4