Giant Cell Arteritis (GCA)

Giant Cell Arteritis (GCA) is a chronic inflammatory autoimmune disease that affects the large and medium-sized arteries, especially those in the head, neck, and upper body. Most commonly, it involves the temporal arteries on the sides of the head. The inflammation can narrow or block blood flow, leading to symptoms like headache, scalp tenderness, jaw pain, and vision problems. Without treatment, GCA can lead to permanent vision loss or stroke.

New, persistent headache (especially at the temples); Scalp tenderness (pain when brushing hair); Jaw pain when chewing (jaw claudication); Vision changes, including blurred vision or sudden blindness in one eye; Fatigue, fever, or weight loss; Muscle aches (especially shoulders and hips, may overlap with polymyalgia rheumatica); Tender or thickened temporal arteries.

Autoimmune vasculitis - the immune system attacks the blood vessels. Exact cause is unknown, but contributing factors include aging (almost exclusively affects adults over 50), genetics (certain HLA types), and environmental factors such as infections that may trigger onset.

Blood tests: Elevated ESR (erythrocyte sedimentation rate), Elevated CRP (C-reactive protein), Mild anemia; Temporal artery biopsy (confirms diagnosis); Ultrasound of the temporal arteries; MRI or PET scans for large-vessel involvement.

High-dose corticosteroids (e.g., prednisone) - started immediately to prevent vision loss; Tapering over time under close monitoring; Tocilizumab (Actemra) - a biologic approved for GCA in some cases; Aspirin may be used to reduce stroke risk; Bone protection (calcium, vitamin D, bisphosphonates) if on long-term steroids.

With early treatment, most people recover well and avoid complications. Long-term steroid use may lead to side effects like osteoporosis or diabetes. Vision loss, if it occurs, is often permanent. Relapses are common and require careful monitoring.

Estimated at 200 per 100,000 people over age 50. Most common in older adults, especially women of Northern European descent. Rare in people under 50.