A 58-year-old man presents with a 3-week history of progressive headache, jaw claudication, and visual blurring. Examination reveals temporal artery tenderness and reduced visual acuity in the left eye. ESR is 92 mm/h and CRP is 8.5 mg/dL. What is the most appropriate immediate next step in management?

Explanation

## Clinical Scenario Analysis This patient has **giant cell (temporal) arteritis (GCA)** with **impending vision loss** — a medical emergency. ### Key Clinical Features - Age >50 years - Temporal artery tenderness (palpable abnormality) - Jaw claudication (pathognomonic for GCA) - Visual symptoms (amaurosis fugax or reduced acuity) - Markedly elevated inflammatory markers (ESR 92, CRP 8.5) **Key Point:** Vision loss in GCA is caused by **anterior ischemic optic neuropathy (AION)** due to vasculitis of the posterior ciliary arteries. Once vision is lost, it is **irreversible**. The risk of blindness is ~50% if untreated and can occur within days. ### Why Immediate High-Dose Corticosteroids? **High-Yield:** In GCA with **visual symptoms or signs**, corticosteroids must be initiated **immediately** — before biopsy confirmation — to prevent irreversible blindness. This is the only situation in vasculitis where treatment precedes diagnostic confirmation. **Mnemonic: VISION LOSS = URGENT STEROIDS** - V = Vasculitis (GCA suspected) - I = Immediate high-dose IV corticosteroids - S = Start before biopsy if vision threatened - I = Intravenous methylprednisolone 1 g daily × 3–5 days - O = Oral prednisolone 1 mg/kg/day after IV phase - N = Never delay for biopsy when vision at risk ### Management Algorithm ```mermaid flowchart TD A["Suspected GCA with visual symptoms"]:::outcome --> B{"Vision loss present?"}:::decision B -->|"Yes (AION/amaurosis fugax)"| C["Start IV methylprednisolone 1 g daily immediately"]:::urgent B -->|"No visual symptoms"| D["Temporal artery biopsy first"]:::action C --> E["Arrange TAB within 1 week (does not delay treatment)"]:::action E --> F["Continue IV × 3–5 days, then oral prednisolone 1 mg/kg/day"]:::action D --> G["If biopsy positive: start oral prednisolone"]:::action D --> H["If biopsy negative: consider alternative diagnosis"]:::outcome ``` ### Rationale for Correct Answer **Intravenous methylprednisolone 1 g daily immediately** is correct because: 1. **Prevents blindness**: IV corticosteroids achieve higher intraocular concentrations faster than oral therapy. 2. **Biopsy is not delayed**: Temporal artery biopsy can still be performed within 1–2 weeks; corticosteroids do not significantly affect histopathology if done within this window. 3. **Standard of care**: American College of Rheumatology (ACR) and European League Against Rheumatism (EULAR) guidelines recommend immediate high-dose corticosteroids for GCA with visual manifestations. 4. **Reversibility window**: Vision loss from AION is irreversible after ~48–72 hours; treatment delay risks permanent blindness. **Clinical Pearl:** Temporal artery biopsy should show **granulomatous inflammation with giant cells and intimal proliferation**. However, biopsy sensitivity is only ~80–90% (skip lesions); a negative biopsy does not exclude GCA if clinical suspicion is high. **High-Yield:** After IV methylprednisolone × 3–5 days, transition to oral prednisolone 1 mg/kg/day (typically 40–60 mg/day), then taper over 12–24 months based on clinical response and inflammatory markers.