What is the treatment for temporal arteritis, specifically giant cell arteritis?

Treatment of Temporal Arteritis (Giant Cell Arteritis)

The treatment of giant cell arteritis (GCA) requires immediate initiation of high-dose glucocorticoids, with consideration of adding tocilizumab as a glucocorticoid-sparing agent to reduce relapse rates and minimize steroid-related complications. 1, 2

Initial Treatment Approach

For GCA Without Visual Symptoms:

• Start high-dose oral glucocorticoids (prednisone 1 mg/kg/day, maximum 60 mg/day) immediately upon clinical suspicion, even before biopsy confirmation 1
• Maintain initial high-dose for one month before beginning gradual taper 1
• Consider adding tocilizumab (FDA-approved for GCA) at initiation of treatment to reduce cumulative glucocorticoid exposure 3, 1

For GCA With Threatened Vision Loss:

• Administer intravenous pulse methylprednisolone (500-1000 mg/day for 3 days) immediately 1, 2
• Do not delay oral glucocorticoid treatment while arranging for IV therapy 2
• After IV pulse therapy, transition to high-dose oral prednisone (1 mg/kg/day) 2
• Visual recovery is uncommon once vision loss has occurred, making immediate treatment crucial 2

Diagnostic Confirmation

• Arrange temporal artery biopsy as soon as possible, ideally within 2 weeks of starting glucocorticoids 1
• Obtain a long-segment biopsy specimen (>1 cm) to improve diagnostic yield 1, 4
• Consider noninvasive vascular imaging to evaluate large vessel involvement 1
• In the US, temporal artery biopsy remains the gold standard over ultrasound or MRI due to limited expertise with these imaging modalities 1

Glucocorticoid Tapering

• After 1 month of high-dose therapy, begin gradual taper 1
• Avoid alternate-day dosing, which increases risk of relapse 1
• By 3 months, aim for glucocorticoid dose of 10-15 mg/day 1
• Target ≤5 mg/day after 1 year, though some patients may require longer treatment 2
• Guide tapering by clinical symptoms and normalization of inflammatory markers 2

Adjunctive Therapy

• Add tocilizumab to glucocorticoids as first-line therapy, especially for patients at high risk of steroid-related complications 1, 3
• Tocilizumab (162 mg subcutaneous weekly) is FDA-approved for GCA and has demonstrated efficacy in reducing relapse rates 3
• For patients with extracranial large vessel involvement, combination therapy with glucocorticoids and a non-glucocorticoid immunosuppressive agent is recommended 1
• Consider methotrexate as an alternative steroid-sparing agent if tocilizumab is contraindicated 5

Management of Relapses

• For disease relapse with cranial ischemic symptoms, add a non-glucocorticoid immunosuppressive agent and increase glucocorticoid dose 1
• Tocilizumab is preferred over methotrexate for relapsing disease with cranial ischemia 1
• For relapse while on moderate-to-high dose glucocorticoids, add a non-glucocorticoid immunosuppressive drug 1

Monitoring

• Implement long-term clinical monitoring for all patients, even those in apparent remission 1
• Isolated elevation of inflammatory markers without clinical symptoms does not necessarily require treatment escalation 1
• Monitor for glucocorticoid-related adverse effects and provide appropriate prophylaxis (e.g., bone protection) 1

Prognosis and Complications

• GCA is a disease of variable duration, often requiring years of treatment 6
• Without treatment, risk of vision loss in the second eye is as high as 50% if one eye is already affected 2
• Visual loss occurs in 15-35% of patients with GCA, primarily before initiation of therapy 2
• Glucocorticoid-related adverse events are common (86% of patients) with long-term therapy 1

Early diagnosis and prompt treatment are essential to prevent irreversible complications such as vision loss in GCA. The combination of glucocorticoids with tocilizumab offers the best approach to control disease activity while minimizing steroid exposure.