A 58-year-old Indian man presents with a 3-month history of progressive headache, jaw claudication, and vision loss in the right eye. On examination, he has temporal artery tenderness and reduced visual acuity (6/36 right eye). Blood pressure is 145/88 mmHg. Laboratory investigations show: ESR 92 mm/hr, CRP 8.5 mg/dL, hemoglobin 9.8 g/dL. Temporal artery biopsy shows granulomatous inflammation with giant cells. What is the most appropriate next step in management?

Explanation

## Diagnosis: Giant Cell Arteritis (Temporal Arteritis) **Key Point:** This patient presents with the classic triad of GCA: headache, jaw claudication, and vision loss (amaurosis fugax progressing to permanent loss). The temporal artery tenderness, elevated inflammatory markers (ESR 92, CRP 8.5), and biopsy showing granulomatous inflammation with giant cells confirm the diagnosis. **High-Yield:** Vision loss in GCA is an ophthalmologic emergency due to anterior ischemic optic neuropathy (AION) from vasculitis of the posterior ciliary arteries. Once vision is lost, it is often irreversible; therefore, treatment must be aggressive and immediate. **Clinical Pearl:** The presence of permanent vision loss (6/36 acuity) indicates ischemic optic neuropathy and mandates urgent high-dose corticosteroid therapy to prevent further visual deterioration and contralateral eye involvement. ## Management Algorithm ```mermaid flowchart TD A[GCA suspected with vision loss]:::outcome --> B{Vision threatened?}:::decision B -->|Yes - AION present| C[IV methylprednisolone 1g daily x 3 days]:::action B -->|No - systemic only| D[Oral prednisolone 1 mg/kg/day]:::action C --> E[Followed by oral prednisolone 1 mg/kg/day]:::action D --> F[Taper over 12-18 months]:::action E --> F F --> G[Add methotrexate if steroid-dependent]:::action G --> H[Monitor ESR/CRP, visual acuity]:::outcome ``` **Key Point:** Intravenous methylprednisolone is preferred over oral steroids alone when vision loss is present, as it achieves higher tissue concentrations and may prevent further ischemic complications. **Mnemonic:** GCA-VISION = **G**ranulomatous inflammation, **C**ell arteritis, **A**cute vision loss → **V**ery high-dose IV steroids, **I**mmediate treatment, **S**ystemic corticosteroids, **I**nflammatory markers monitored, **O**phthalmic emergency, **N**o delay. ## Dosing & Follow-up | Parameter | Details | | --- | --- | | **IV induction** | Methylprednisolone 1 g IV daily × 3 days (for vision-threatening disease) | | **Oral maintenance** | Prednisolone 1 mg/kg/day (max 80 mg/day), then taper by 10 mg every 2–4 weeks | | **Duration** | 12–18 months minimum | | **Monitoring** | ESR, CRP at baseline, 2–4 weeks, then monthly; ophthalmology review; bone protection (calcium + vitamin D ± bisphosphonate) | | **Second-line agent** | Methotrexate 15–25 mg/week if steroid-dependent or intolerant | **Warning:** Delaying high-dose corticosteroids in the presence of vision loss significantly increases the risk of permanent blindness and contralateral eye involvement.