A 58-year-old Indian man presents with a 3-week history of progressive headache, jaw claudication, and visual blurring in the left eye. On examination, his left temporal artery is tender and non-pulsatile. ESR is 92 mm/h, CRP is 8.5 mg/dL, and hemoglobin is 10.2 g/dL. Fundoscopy shows optic disc pallor. What is the most appropriate next step in management?

Explanation

## Diagnosis: Giant Cell Arteritis (Temporal Arteritis) ### Clinical Presentation This patient has classic features of GCA: - Age >50 years - Headache and jaw claudication (pathognomonic) - Visual symptoms (amaurosis fugax or impending central retinal artery occlusion) - Tender, non-pulsatile temporal artery - Markedly elevated ESR and CRP - Normocytic anemia **Key Point:** Optic disc pallor and visual blurring indicate **imminent or established arteritic anterior ischemic optic neuropathy (AAION)** — a medical emergency. ### Management Algorithm ```mermaid flowchart TD A[Suspected GCA with visual symptoms]:::outcome --> B{Imminent vision loss?}:::decision B -->|Yes| C[Start high-dose corticosteroids IMMEDIATELY]:::urgent B -->|No| D[Start corticosteroids same day]:::action C --> E[Temporal artery biopsy within 1-2 weeks]:::action D --> E E --> F{Biopsy positive?}:::decision F -->|Yes| G[Continue/taper corticosteroids per protocol]:::action F -->|No| H[Consider alternative diagnosis]:::outcome ``` **High-Yield:** The **temporal artery biopsy does NOT need to be done before starting corticosteroids** when vision-threatening complications are present. Delaying therapy risks permanent blindness. Biopsy can be performed within 1–2 weeks of starting treatment without significantly reducing diagnostic yield (biopsy remains positive for weeks to months after steroid initiation). **Clinical Pearl:** The presence of optic disc pallor and visual blurring makes this a **vision-threatening emergency**. Corticosteroids must be initiated immediately to prevent irreversible vision loss. **Mnemonic — GCA Red Flags:** **HEADACHE** - **H**eadache (temporal, occipital) - **E**levated ESR/CRP - **A**rteritis (temporal artery tenderness) - **D**iplopia or visual loss - **A**nemia (normocytic) - **C**laudication (jaw, tongue, limb) - **H**yperviscocity symptoms - **E**rythrocyte sedimentation rate >50 mm/h ### Why Biopsy Is Still Needed Temporal artery biopsy remains the gold standard for diagnosis, confirming granulomatous inflammation with giant cells. However, **it must not delay therapy** in vision-threatening disease. ### Dosing Initial corticosteroid: **Prednisolone 1 mg/kg/day** (or methylprednisolone 1 g IV daily × 3 days if AAION present), then taper over months based on clinical response and inflammatory markers. [cite:Harrison 21e Ch 378]