Overview of Giant Cell Arteritis

Giant cell arteritis (also referred to as GCA, cranial arteritis, or temporal arteritis) is a type of vasculitis, which is inflammation of the blood vessels. The vessels most commonly involved in GCA are the arteries of the head and scalp, especially near the temples. Sometimes arteries of the neck, arms, chest, and abdomen are involved as well.

Symptoms of Giant Cell Arteritis

The most common symptom associated with GCA is a new headache, typically near the temples, but it can occur anywhere over the skull.

Other effects include:

• Generalized symptoms: You can experience fatigue, loss of appetite, weight loss, flu-like sensations, and prolonged or recurrent fevers.
• Mouth and jaw involvement: Jaw pain or facial, tongue, or throat pain can occur but are not common.
• Dizziness: It's also possible to experience dizziness or problems with balance.
• Vision: GCA can affect the blood supply to the eye, causing blurred vision, double vision, or blindness.

If you develop vision loss with GCA, it can occur suddenly and it may not be reversible. That's why it's crucial that you seek medical treatment immediately if you have any symptoms of GCA. Early treatment may prevent permanent vision loss.

People have a tendency to wait and see if symptoms subside. In the case of GCA, that could prove to be a regrettable approach. 

Diagnosing Giant Cell Arteritis

There is no diagnostic test that can definitively confirm the diagnosis of GCA, but there are some tests that are used to help in diagnosis of the condition.

The sedimentation rate (ESR), measured with a blood test, is typically elevated with GCA. But elevated ESR is indicative of non-specific inflammation and can be present with a variety of inflammatory conditions.

Temporal artery ultrasound or computerized tomography (CT) may show swelling or inflammation in or near the temporal artery, but these tests often don't show any abnormalities in GCA.

A biopsy of a small piece of the temporal artery may show inflammation or the appearance of giant cells when examined microscopically.

Treatment of Giant Cell Arteritis

Treatment for giant cell arteritis should begin as soon as the condition is suspected and even before there is confirmation from biopsy results. Sometimes treatment can reduce inflammation and may make the biopsy sample appear normal.

Often, the condition is treated with prednisone, at a dose of one milligram (mg)/ milligram (kg). Typically, the treatment for GCA is 40 to 60 milligrams (mg) of prednisone per day. Sometimes prednisone is combined with disease-modifying anti-rheumatic drugs (DMARDs) such as methotrexate or with tocilizumab.

While headaches and some other symptoms tend to resolve quickly with treatment, this dose of corticosteroids is continued for a month, slowly reduced to five-10 mg per day for several more months, and discontinued after one or two years.

As your corticosteroid dose is reduced, symptoms can return and should rapidly improve with a temporary increased dose of corticosteroids. Be sure to check with your doctor and don't make any changes to your dose on your own.

Once you have steroid-free remission, a recurrence of GCA is considered unlikely and rare.

Prevalence of Giant Cell Arteritis and Statistics

GCA affects older adults, usually over the age of 50. About 50% of patients with GCA also have symptoms of polymyalgia rheumatica. Symptoms of these two conditions can occur simultaneously or separately. Females are more commonly affected by GCA than men, and whites experience the condition at higher rates more than non-whites. It has been estimated that 200 per 100,000 people over 50 years old develop GCA.