Suspected giant cell arteritis with recent visual loss, on steroids and diabetic
A 78-year-old woman presents with sudden painless loss of vision in the right eye 6 hours ago. For the past 3 weeks she has had bitemporal headache, scalp tenderness when combing her hair, and jaw pain when chewing. Right VA is counting fingers at 1 metre with a relative afferent pupillary defect; the right disc is swollen and pale and the left fundus is normal. ESR is 82 mm/h and CRP 68 mg/L. Her GP started oral prednisolone 60 mg daily 2 days ago, after the headache began but before the visual loss. She has type 2 diabetes (HbA1c 8.5%), a duodenal ulcer 5 years ago, and is a glaucoma suspect on no drops. Temporal artery biopsy is available at a hospital 2 hours away, with the next slot in 10 days. Carotid Doppler is not available on site. She lives alone and is otherwise independent.
1. Should she receive high-dose intravenous methylprednisolone now, and what does the 2 days of oral prednisolone mean for the diagnosis and for the biopsy?
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Yes to immediate high-dose steroid; the route is a judgement call.
- The right eye's vision is already lost. The purpose of treatment now is to protect the fellow eye, at high risk over the next days to weeks, and to salvage any residual right eye vision.
- There is no good randomised evidence that intravenous methylprednisolone (for example 500–1000 mg daily for 3 days) restores vision better than oral prednisolone 60 mg once loss is established, but it is widely used and acts faster where there is threatened fellow-eye involvement, bilateral disease, or loss within the last 24 hours with potentially reversible ischaemia. Given that she is functionally monocular with a swollen disc, escalating to pulses is reasonable.
Never delay steroids for a biopsy. The 2 days of prednisolone does not invalidate it: the characteristic histological changes remain identifiable for up to about 2 weeks after starting steroids, though sensitivity falls. Therefore:
- A negative biopsy does not exclude the diagnosis in a 78-year-old with jaw claudication, scalp tenderness, ESR above 80 and visual loss. Treat on clinical grounds.
- Do not wait 10 days for the slot - request an urgent biopsy or proceed clinically and let histology follow.
- Temporal artery ultrasound (halo sign) is a useful non-invasive adjunct if biopsy cannot be done promptly. Carotid Doppler is irrelevant here and must not delay treatment.
2. What investigations and safety measures would you arrange before or alongside the first high-dose dose, and what prophylaxis does she need?
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Alongside, not before, the first dose:
- Capillary and laboratory glucose - she is diabetic with HbA1c 8.5%, and high-dose steroid will cause hyperglycaemia. Arrange a variable-rate insulin infusion or a written sliding-scale plan with the diabetes team for the duration of pulses.
- Blood pressure, full blood count (steroids cause neutrophilia and lymphopenia), urea and electrolytes, liver function, bone profile, vitamin D, HbA1c.
- Baseline IOP, gonioscopy and dilated fundoscopy - she is a glaucoma suspect, and steroid response can raise IOP substantially within weeks. Measure before, not after.
- Fracture risk assessment or DEXA, with bone protection: alendronate plus calcium and vitamin D for a 78-year-old facing many months of steroid.
- Gastroprotection with a proton-pump inhibitor given the duodenal ulcer, and consider H. pylori testing.
- Vaccination status - pneumococcal, influenza, shingles (avoid live vaccines on high-dose steroid) and COVID-19.
- Latent infection screen if long-term therapy is planned: hepatitis B and TB risk factors. Ask pre-emptively about mood change, insomnia and ulcer symptoms.
What you must not do is delay the first dose for any of these. Take the samples, give the steroid, and correct the glucose and blood pressure afterwards.
3. Outline the taper, monitoring and role of steroid-sparing therapy over the next 18 months.
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Maintenance and taper:
- Continue prednisolone 60 mg (or complete 3 days of intravenous pulses then convert to oral 60 mg) for 2–4 weeks, rechecking symptoms, ESR and CRP. Resolution of symptoms with normalising markers is the signal to taper.
- Taper slowly: 5 mg reductions every 2 weeks to 20 mg, then 2.5 mg every 2–4 weeks to 10 mg, then 1 mg every 1–2 months. Total course is usually 12–18 months, often longer.
- Taper on symptoms and markers rather than a fixed calendar. Relapse during taper - return of headache, jaw claudication or any visual symptom - means going back up, not pressing on.
Monitoring: acuity, pupils and fundoscopy at every visit, with explicit instructions that any new visual symptom means an immediate telephone call and an immediate dose increase, not a routine appointment. Also blood pressure, weight, glucose/HbA1c, bone density, mood, cataract and IOP - steroid-induced pressure rise is likely in a glaucoma suspect.
Steroid-sparing therapy: tocilizumab has the best randomised evidence for relapsing or refractory disease and for reducing cumulative steroid exposure; consider it early here, because diabetes and osteoporosis make a long steroid course genuinely hazardous. Methotrexate is used but the evidence is weak; azathioprine and mycophenolate are second-line.
Counselling: aspirin is not protective; she needs a steroid card and sick-day rules; she must never stop prednisolone abruptly; and the eye that matters now is the left one.