Giant Cell Arteritis (Temporal Arteritis)

Giant cell arteritis (GCA) is a serious condition, but it is also controllable, treatable, and often curable.

Giant cell arteritis (GCA) describes inflammation in the walls of arteries. Most often the inflammation occurs in the cranial branches of the carotid artery that supply the head. For that reason, it is also known as temporal arteritis or cranial arteritis.

The cause of the inflammation is still not known, but it results in thickened areas of the artery wall and the formation of giant cells associated with that inflammation. The inflamed artery wall loses its smooth muscle and elastic lining. As it heals the wall thickens and can decrease or completely block blood flow through the damaged area.

GCA often involves the temporal artery that runs from the neck, superficially just under the skin, to the area in front and above the ear. Of more concern is that the ophthalmic artery that supplies blood to the eye can also be affected. If that artery closes off, the result is blindness. For that reason, it is important to quickly make the diagnosis and start treatment immediately.

The cause of giant cell arteritis is not known. The cause of the inflammation and giant cell deposition is not known. There may be an immune response that begins the process, but it has yet to be determined why the body would trigger that immune inflammation.

There is a relationship between GCA and polymyalgia rheumatica, but the symptoms of both diseases may occur at the same time or may develop many years apart.

What triggers giant cell arteritis?

It is uncertain why a person would develop GCA. It occurs in patients older than 50 and the incidence increases with age. Women are more at risk, as are those with northern European and Scandinavian heritage. There may be a genetic predisposition as family clusters may occur. As well, there is a possibility that there may be an environmental trigger.

What does giant cell arteritis feel like?

Giant cell arteritis most often begins as a subtle or sub-acute illness, with non-specific findings like fever, fatigue, muscle aches, and weight loss. However, some people become acutely ill with high fevers.

Headache is a common complaint, and though the temporal artery is most often involved, the headache can be at the forehead (frontal) or back of the head (occipital) or global. The area over the temporal artery, above the ear, may be tender to touch.

Jaw claudication occurs in about half of patients, where chewing can bring on pain and discomfort as the muscles of mastication (chewing) tire, because their blood flow is decreased. The jaw pain gets better when chewing stops and the muscles can rest.

Because the arteries that supply blood to the eye may be involved, transient loss of vision (amaurosis fugax) may occur. The most serious symptom and complication is complete loss of vision and blindness in an eye.

There are no specific risk factors that have been identified that would put a patient at higher risk for eye involvement.

Older patients who present with the complaint of a new headache, or a change in their routine headache pattern should have the diagnosis of giant cell arteritis considered. Any changes in vision and jaw claudication should heighten suspicion. Unexplained fever may direct the provider to search for GCA.

Patients with polymyalgia rheumatica are at higher risk for GCA diagnosis.

The health care provider should take a careful history from the patient and perform a physical examination. There may be findings that artery inflammation is present, or the exam may be completely normal.

Some abnormalities that might be found include thickening and tenderness of the temporal artery, abnormal sounds (bruits) when listening to the carotid arteries in the neck, or decreased pulses in the arms.

Vison should be checked and an eye exam performed to look for evidence of decreased blood flow to the eye.

Laboratory tests will include non-specific markers of inflammation in the body, including erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP).

X-ray, CVT scan, and MRI are of little help. Color doppler ultrasound of the temporal and other arteries may be considered.

Temporal artery biopsy is the procedure of choice to confirm the diagnosis. A surgeon removes part of the temporal artery and it is examined under the microscope to look for changes consistent with the diagnosis of GCA. However, the inflammation does not involve the whole artery and the biopsy may be negative for GCA, even though the disease is present (a false negative test).

Treatment for suspected GCA begins even before the diagnosis is confirmed. High dose steroids (prednisone) taken by mouth is used to decrease inflammation in the artery walls with the hope of decreasing the risk of blindness should arteries to the eye be involved.

• In patients without vision changes, prednisone may be taken by mouth,
• For patients with changes in vision, intravenous steroids are usually given.

The steroids are prescribed for at least 2-4 weeks before being tapered.

Other medications that might be considered include methotrexate and tocilizumab, a monoclonal antibody.

Patients with involvement of the aorta, carotid arteries, or other large blood vessels may be prescribed aspirin.

Giant cell arteritis may cause complete blockage of an artery that might lead to blindness or stroke.

Other complications depend upon the artery that is affected. The aorta and carotid arteries may be involved and it is routine to have them evaluated and screened for inflammation or aneurysm.

High dose steroids may have significant complications including bone loss and fractures, muscle inflammation and muscle wasting, difficulty in controlling pre-existing diabetes, and increasing the risk of infection.

With prompt treatment, the prognosis for GCA is reasonable, with most patients having their symptoms controlled and resolved in one to two years. Some patients develop a chronic condition that needs care stretching over many years.

Routine follow up with physical exam and blood tests using ESR and CRP to monitor inflammation may be recommended initially every 3 months.

There can be early relapses within the first year. Usually, a relapse occurs when the prednisone dosage has been tapered too low to prevent artery inflammation. Headache is the most common symptom.

Late recurrence of GCA is a possibility.

How long can you live with giant cell arteritis?

Most often, giant cell arteritis resolves within one to two years. Some patients may have a chronic disease state where treatment is required for much longer.

Giant cell arteritis cannot be prevented. The goal is early detection and rapid treatment to prevent complications.