Why is corticosteroid (e.g. prednisone) treatment initiated first in giant cell arteritis?

From the Guidelines

Corticosteroids like prednisone are initiated first in giant cell arteritis (GCA) because they rapidly suppress inflammation and prevent vision loss, which is the most feared complication of this condition. Treatment should begin immediately upon suspicion of GCA, typically with high-dose oral prednisone at 40-60mg daily (or 1mg/kg/day), without waiting for biopsy confirmation 1. For patients with visual symptoms, intravenous methylprednisolone (0.25-1g daily for up to 3 days) may be used initially 1. The high dose is maintained for 2-4 weeks until symptoms resolve and inflammatory markers normalize, then gradually tapered over 12-18 months to minimize relapse risk. This aggressive approach is necessary because GCA causes inflammation of medium and large arteries, particularly the temporal arteries, which can lead to irreversible blindness within hours to days if left untreated.

Key Considerations

• The risk of permanent vision loss outweighs the considerations of side effects like osteoporosis, diabetes, and weight gain in initial management 1.
• Biopsy confirmation should not be imperative to initiate treatment in cases in which GCA seems to be the most likely diagnosis 1.
• Laboratory testing such as elevated sedimentation rate or C-reactive protein and a compatible semiology may be the only available elements to make a decision to initiate treatment 1.
• Ultrasound finding of a halo sign surrounding a temporal artery may be helpful in diagnosis giant cell arteries 1.

Treatment Approach

• High-dose corticosteroids should be initiated quickly within the first 24 hours after symptoms onset to reduce the risk of permanent blindness and to increase the chance of visual recovery 1.
• The dose of prednisone should be tapered to a target dose of 15–20 mg/day within 2–3 months and after 1 year to ≤5 mg/day 1.
• Referral to an experienced centre for further work-up including large-vessel imaging is recommended 1.

From the Research

Initiation of Corticosteroid Treatment in Giant Cell Arteritis

• Corticosteroids, such as prednisone, are the main treatment for giant cell arteritis (GCA) 2, 3.
• The choice of initial prednisone dosage takes into account the disease severity and comorbidities to reduce drug side effects 2.
• Corticosteroids are effective in controlling the disease, but their use is associated with predictable and occasionally serious side effects 3.
• The initiation of corticosteroid treatment first in GCA is due to its ability to quickly reduce inflammation and prevent severe complications, such as visual loss or stroke 4.

Rationale for Corticosteroid Treatment

• Corticosteroids have a rapid onset of action, which is essential in preventing severe complications of GCA 2, 3.
• The use of corticosteroids as the initial treatment allows for the quick control of symptoms and the reduction of inflammation 5, 6.
• While other treatments, such as methotrexate, can be used as adjunctive therapy to reduce the dose of corticosteroids, corticosteroids remain the cornerstone of therapy for GCA 2, 5, 6.

Benefits of Early Corticosteroid Treatment

• Early initiation of corticosteroid treatment can reduce the risk of severe complications, such as visual loss or stroke 3, 4.
• Corticosteroids can quickly improve symptoms and reduce inflammation, leading to better outcomes for patients with GCA 2, 5, 6.
• The use of corticosteroids as the initial treatment allows for the rapid control of the disease, which is essential in preventing long-term damage and reducing the risk of relapse 2, 3, 4.