Giant Cell Arteritis can cause optic nerve ischaemia leading to rapid onset of irreversible, bilateral blindness. It should be considered in any patient aged over 50 presenting with new headache or visual symptoms.
When assessing a patient these features which make the diagnosis more or less likely
| More Likely | Less likely |
| Age >55 | Age <55 (diagnosis probably excluded below age 50) |
| Headache | No Headache (diagnosis probably excluded unless taking steroids) |
| Visual Symptoms (transient or lasting visual loss or diplopia) | No visual loss or diplopia |
| Scalp tenderness or temporal artery tenderness. (High specificity) | No scalp tenderness |
| Jaw Claudication (High specificity) | No Jaw Claudication |
| Systemically unwell: Fatigue, weight loss | Systemically Well |
| Polymyalgia Rheumatica (PMR): Hip and Shoulder pain and stiffness. | No features of PMR |
| Raised ESR or CRP (not reliable if already on steroids) | Normal ESR / CRP |
Based on the considerations above, you can then decide which of the following options would be appropriate
- No features of GCA, no treatment or investigation. Consider safety net.
- Low risk of GCA, no treatment, but CRP and review within a few days with results. Advise to seek urgent attention if visual symptoms.
- Moderate to High risk of GCA, Commence oral steroids at 0.5 to 1mg/kg prednisolone daily, with plan to stop if CRP normal. Consider Temporal Artery Biopsy (TAB) if marked clinical response, but CRP normal. (Caution with steroids if diabetic)
- Visual Symptoms plus other features of GCA: Give oral steroids and refer immediately to local eye department for urgent assessment and probably pulsed methylprednisolone.
- CRP is 97.5% sensitive, combined CRP / ESR is 99.2% sensitive, which is not clinically significantly better: Test CRP alone. See link here.
Long term management is often supervised by a consultant rheumatologist, the patient will usually require Steroid treatment for 1-3 years, so a TAB is usually required to confirm the diagnosis, within 7 days of commencing steroids. They will also typically be commenced on Aspirin, lansoprazole, Alendronic acid, Adcal-D3.
Further reading:
- Why are the retinal artery’s affected?
- What other vessels are vulnerable?
- When could a normal ESR be falsely reassuring?
- When is the risk of blindness highest?
