A 58-year-old Indian man presents with a 3-month history of progressive headache, jaw claudication, and vision loss in the left eye. Examination reveals tenderness over the left temporal artery and a visual acuity of 2/60 in the left eye. Erythrocyte sedimentation rate (ESR) is 95 mm/h and C-reactive protein (CRP) is 12 mg/dL. Temporal artery biopsy shows granulomatous inflammation with giant cells and fragmentation of the internal elastic lamina. What is the most appropriate next step in management?

Explanation

## Diagnosis: Giant Cell Arteritis (Temporal Arteritis) ### Clinical Presentation Recognition **Key Point:** This is a classic presentation of giant cell arteritis (GCA): elderly patient with temporal headache, jaw claudication, vision loss, elevated inflammatory markers, and biopsy-confirmed granulomatous inflammation with giant cells. ### Pathophysiology Giant cell arteritis is a large-vessel vasculitis affecting the temporal, vertebral, and carotid arteries. The granulomatous inflammation with giant cells and internal elastic lamina fragmentation is pathognomonic. Vision loss (amaurosis fugax or permanent) occurs due to involvement of the posterior ciliary arteries and represents a medical emergency. ### Management Principles | Aspect | Details | |--------|----------| | **Immediate action** | High-dose corticosteroids (IV methylprednisolone 500–1000 mg daily × 3–5 days, then oral prednisolone 40–60 mg daily) | | **Rationale** | Prevents irreversible vision loss and other ischemic complications | | **Timeline** | Biopsy-confirmed diagnosis allows definitive treatment initiation | | **Steroid taper** | Gradual reduction over 12–24 months based on clinical response and ESR/CRP normalization | | **Adjunctive agents** | Methotrexate or tocilizumab (IL-6 inhibitor) may be added for steroid-sparing effect in relapsing disease | **High-Yield:** Vision loss in GCA is an ophthalmologic emergency. Corticosteroids must be started immediately once the diagnosis is suspected clinically, even before biopsy, to prevent irreversible blindness. The biopsy result confirms the diagnosis retrospectively. ### Why Option 3 (IV methylprednisolone) Is Correct In a patient with biopsy-confirmed GCA and vision loss, intravenous methylprednisolone followed by high-dose oral prednisolone with gradual tapering is the gold standard. This approach: 1. Achieves rapid anti-inflammatory effect to prevent further ischemic complications 2. Allows controlled tapering to minimize long-term steroid toxicity 3. Is supported by major rheumatology guidelines (ACR, EULAR) **Clinical Pearl:** The presence of vision loss (amaurosis fugax or permanent visual loss) mandates aggressive induction therapy with IV corticosteroids, not oral monotherapy. [cite:Harrison 21e Ch 319]