Giant cell arteritis (GCA) refers to when the linings of the arteries are inflamed. Arteries are blood vessels that usually take blood away from the heart. These blood vessels help to nourish the eye with oxygen and other nutrients. A swelling of the arteries reduces blood flow which can cause sudden, painless loss of vision.
The arteries that are affected by GCA include those in the neck, upper body, arms and especially the temple.
Also Known As
- Temporal arteritis – It affects the cranium (head) or temples
Causes and Risk Factors
GCA is caused by the swelling of the arteries. However, the cause of the inflammation of the arteries is unknown. It is believed that the immune system is responsible for the abnormal attacks on the walls of the artery. Also, genetics and environmental factors like infections may be responsible. It is also possible that GCA is age-related because it is rare in people below the age of 50. People at risk of developing GCA include:
- Older people usually above 50 years old although GCA is most popular with those in their 70s and 80s
- Women who are twice as likely to develop GCA as men
- Scandinavian people who have a higher likelihood of developing GCA. The condition is rare among African-Americans and Asians
- Those with a family history of GCA
- People with polymyalgia rheumatica (PMR) are at an increased risk of getting GCA. PMR is an inflammatory disorder which produces pain and tautness in the shoulder and hip. Severe infections and high doses of antibiotics can cause PMR
Signs & Symptoms
GCA presents varied symptoms. They may include:
- A new, persistent headache
- Head pain that affects both temples
- Scalp tenderness especially around the temples (pain when combing hair)
- Pain and stiffness in the arms, hips and neck
- Sudden loss of vision in one eye
- Blurred or double vision especially in people with jaw pain
- Blindness in one eye followed by the other if the condition is not arrested
- Flu-like symptoms, fatigue and fever
- Weight loss that is not intended
- Pain in the jaw particularly when chewing or opening the mouth wide
- Problems with balance and coordination
The eye care professional will conduct a detailed eye examination. In addition, he/she will:
- Check visual acuity
- Conduct a visual field test to see if the individual has lost peripheral vision
- Measure eye pressure
- Do a dilated exam to check for damage in the retina or optic nerve
- Examine the head to show whether the scalp is sensitive and has a tender thick artery on one side. This artery may have a weak pulse or no pulse at all
- Order blood tests to confirm the presence of the inflammation. Abnormal test results mean that further tests are required. The professional will recommend a biopsy of a sample from the temple artery. Also, an erythrocyte sedimentation rate test can measure the speed at which the red blood cells drop to the base of a tube of blood. GCA may be present if the red blood cells fall rapidly. Another blood test is the C-reactive protein test which measures a substance produced by the liver if an inflammation is present
- Do imaging tests such as magnetic imaging resonance (MRI) to check that the arteries are healthy
Treatment of GCA is directed towards reducing or eliminating the inflammation in the arteries
The eye doctor will recommend a high dosage of steroids (prednisone) to clear the inflammation in the artery. He/she prescribes steroid tablets even before GCA has been confirmed. This is because prompt treatment of GCS may prevent vision loss. The high dosage may continue for a month or so before being lowered.
The doctor may give a tocilizumab injection to help with the inflammation. Tocilizumab, however, is not ideal for patients who have had certain diseases or infections. These include Tuberculosis, HIV, Diabetes and bacterial, fungal and viral infections.
Also, a daily low dose of aspirin may be prescribed to prevent a stroke.
Patients who are allowed to take tocilizumab can inject themselves with the drug. However, they can only do so after being taught how to. The patient should also practice proper nutrition, plenty of exercises and rest. This will help with any side effects of the steroids.
Treatment for GCA patients may last as long as two years. However, most patients begin to feel better as soon as they start treatment.
Relapses are common with GCA even with treatment.
GCA can lead to permanent loss of vision. Diminished blood flow to the eye can cause sudden, painless irreversible vision. However, such patients are taught how to make the most of their remaining vision.
Aortic aneurysm can occur as a result of GCA. An aneurysm develops in a weakened blood vessel. It can burst leading to internal bleeding which is life-threatening. This condition can occur years after GCA has been diagnosed. Consequently, a patient needs annual X-rays of the chest and other imaging tests to monitor the aorta.
People with GCA are likely to develop PMR where they will experience pain and tautness in the shoulders, neck and hips.
Though rare, GCA can lead to a stroke.
The patient will need careful monitoring when on steroids. This is because steroid drugs have side effects such as increasing a patient’s chance of having broken bones. Other side effects include hypertension, osteoporosis and muscle weakness. Vitamin D supplements and calcium can help to prevent the loss of bone.