Updated November 02, 2014.

Written or reviewed by a board-certified physician. See About.com's Medical Review Board.

Headache itself is not always a primary disorder, but rather a symptom of another underlying disease process. In giant cell arteritis, also known as temporal arteritis, headache affects more than two-thirds of patients and is the most frequent initial complaint.

What is Giant Cell Arteritis?

Giant cell arteritis or GCA is a large and medium blood vessel vasculitis. Vasculitis refers to inflammation of blood vessels.

GCA mostly affects the branches of the external carotid artery, a large artery in the neck. The inflammation of specific arteries in GCA impairs blood flow, causing various symptoms like headache, vision changes, and jaw pain when chewing.

What Questions Will Your Doctor Ask?

Your doctor will ask certain questions to determine whether or not she suspects GCA. Due to the fact that this disorder rarely occurs in young individuals, your doctor will likely only probe into these specific questions if you are age 50 or older.

• Is your headache new? For most adults suffering from GCA, their headache is not only severe but new, meaning they have never felt this type of head pain before.
• Where is your headache? Typically, the headache of GCA is located in the temples, but it can be more generalized or localized to the forehead or back of the head. It may occur bilaterally (both sides of the head) or just on one side. With temple pain, individuals may complain of discomfort when putting on a hat or combing their hair.

• Do you have a fever or chills? Your doctor will take your temperature, as fever is commonly seen in those with GCA.
• How do you feel? Classically, individuals with GCA feel and look lousy. In addition to the headache, they may note weight loss, fatigue, a loss of appetite, and/or a cough.
• Do you have any aches? A condition called polymyalgia rheumatic (PMR), which causes morning aches and stiffness in the hips, shoulders, and neck, has been associated with GCA.  So, if you have been diagnosed with PMR and have a new headache, your doctor may put two and two together and suspect a diagnosis of GCA.
• Does your jaw hurt when chewing? This is called jaw claudication and is seen in about one half of patients with GCA. The jaw pain is often felt near the temporomandibular joint (TMJ) and occurs after eating food that requires rigorous chewing, like red meat or a bagel.
• Do you have any vision changes? There are a number of visual changes that may occur in patients with GCA such as: complete loss of vision in one eye or double vision (diplopia). It is sometimes this feared symptom that leads individuals to finally seek medical attention.

Classification

The American College of Rheumatology developed criteria to differentiate giant cell arteritis from other forms of vasculitis. The presence of 3 or more of the 5 criteria correlate with a 93.5% sensitivity and 91.2% specificity. This means that there is a low chance for both false-negatives and false-positives when your doctor makes the diagnosis. Here are the five criteria:

• Age = 50
• New onset of localized headache
• Tenderness at the site of the temporal artery (artery that is superficially located in your temples) or decreased temporal artery pulse
• An erythrocyte sedimentation rate (ESR) = 50mm/hour*
• A biopsy of the temporal artery consistent with necrotizing arteritis**

*ESR is a marker of body inflammation and is characteristically high in those with GCA.

**Necrotizing arteritis describes the inflammatory cell changes seen in a biopsy sample of an individual with GCA. A doctor, known as a pathologist, visualizes these cell changes using a microscope.

What Will My Doctor Do If She Suspects GCA?

If your doctor suspect GCA as the cause of your headache, than she will likely refer you for a temporal artery biopsy to confirm the diagnosis.

Treatment of this disorder entails a long course of high dose glucocorticoids, like prednisone. Duration of therapy can range from several months to years, in order to prevent serious GCA-related complications, like irreversible vision loss. The challenging part is that a high dose of oral steroids, for this duration, has many side effects.

To reduce the dose and duration of glucocorticoid use in GCA, one small study in Arthritis Rheumatism examined initial treatment of GCA with an intravenous glucocorticoid followed by oral glucocorticoid use. This successfully allowed for a lower dose and faster tapering down of the steroids, when compared to the individuals who took oral steroids without an initial intravenous dose.

What Does This All Mean?

If you have a new-onset headache or a change in headache pattern, see your healthcare provider for a proper diagnosis. GCA is a treatable disease that can often mimic other medical conditions. As always, listen to your instincts and be proactive in your healthcare.

<sub>Sources

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Gonzalez-Gay MA, Barros S, Lopez-Diaz MJ, Garcia-Porrua C, Sanchez-Andrade A, Llorca J. Giant cell arteritis: disease patterns of clinical presentation in a series of 240 patients. Medicine (Baltimore). 2005 Sep;84(5):269-76.

Hellmann DB. Temporal arteritis: a cough, toothache, and tongue infarction. JAMA. 2002 Jun 12;287(22):2996-3000.

Hunder GG, Bloch DA, Michael BA, Stevens MB, Arend WP, Calabrese LH et al. The American College of Rheumatology 1990 criteria for the classification of giant cell arteritis. Arthritis Rheum 1990;33(8):1122.

Mazlumzadeh M, Hunder GG, Easley KA, Calamia KT, Matteson EL, Griffing WL, et al. Treatment of giant cell-arteritis using induction therapy with high-dose glucocorticoids: a double-blind, placebo-controlled, randomized prospective clinical trial. Arthritis Rheum 2006 Oct;54(10):3310-8.

Smetana GW & Shmerling RH. Does this patient have temporal arteritis? JAMA. 2002 Jan 2;287(1):92-101.</sub>

DISCLAIMER: The information in this site is for educational purposes only. It should not be used as a substitute for personal care by a licensed physician. Please see your doctor for diagnosis and treatment of any concerning symptoms or medical condition.