Understanding Giant Cell Arteritis (GCA)

What is GCA?

Giant cell arteritis (GCA) is a condition in which the body’s immune system causes inflammation (swelling) in the walls of medium and large arteries — most often the arteries around the temples and scalp, and sometimes larger arteries like the aorta. GCA is a type of vasculitis, which means “inflammation of blood vessels.” It almost always occurs in people age 50 and older.

When these arteries become inflamed, blood cannot flow through them normally. If the arteries that supply the eyes are affected, GCA can cause sudden, permanent vision loss. The good news is that when GCA is found and treated early, vision loss can usually be prevented.

Warning signs and symptoms

GCA can cause one or more of the following. Symptoms can come on gradually or suddenly:

• New headache — often over the temples, and different from past headaches
• Scalp tenderness — soreness when brushing your hair or touching your scalp
• Jaw pain with chewing — aching or fatigue in the jaw while eating
• Vision changes — blurring, double vision, or loss of vision in one or both eyes
• Fevers, night sweats, or weight loss
• Shoulder and hip stiffness — especially in the morning (a related condition called polymyalgia rheumatica)

Why fast diagnosis matters

The most feared complication of GCA is sudden, permanent vision loss, which can happen with little warning. Because treatment is most effective at protecting vision when it is started quickly, GCA is considered a medical urgency. This is the reason our Fast Track Clinic exists: to evaluate people with suspected GCA rapidly so treatment is not delayed.

How GCA is diagnosed

Doctors use a combination of tools to diagnose GCA:

• Your story and exam — your symptoms and a physical examination
• Blood tests — markers of inflammation such as ESR and CRP (note: these can occasionally be normal in GCA)
• Vascular ultrasound — a painless scan that can show inflammation in the artery walls
• Temporal artery biopsy — a small sample of the temporal artery, used in some cases to confirm the diagnosis

How GCA is treated

Treatment is usually started quickly — often before every test is complete — to protect your vision. The mainstay of treatment is corticosteroids (such as prednisone) to calm the inflammation. Many patients also take a steroid-sparing medication, such as tocilizumab, which can help control the disease and reduce the amount of steroids needed over time. Steroids are lowered slowly over months under your doctor’s guidance. Because long-term steroids can affect the bones, your care team will also help protect your bone health.

What to expect at the Fast Track Clinic

If your doctor refers you, you will be contacted for a prompt evaluation that typically includes a vascular ultrasound and an assessment by a rheumatologist. Our goal is to reach a diagnosis quickly so that the right treatment can begin without delay. Please note that referrals come through your doctor — patients should not contact the clinic directly.