Giant Cell Arteritis

What is Giant Cell Arteritis (GCA)?

Giant Cell Arteritis (GCA) is a condition where the body attacks its own blood vessels. This is known as an auto-immune disease.

GCA can affect the main artery in the heart and smaller blood vessels in the head. This can interrupt blood flow. It can also cause pain, inflammation and tenderness around the temples. Because of this, the condition is also known as ‘temporal arteritis’.

Around 1,000 Australians are diagnosed with GCA each year. Treatment is very important because the condition can cause blindness.

What are the symptoms?

Symptoms include:

• New onset of headaches (usually on one side of the head only)
• Fatigue
• Weight loss
• Tender scalp or temples
• Sudden vision loss, blurred or double vision
• Pain in the jaw when eating or talking
• Dizziness
• Problems with coordination and balance
• Persistent sore throat
• Difficulty swallowing
• Fevers and sweats
• Dry cough

What causes it?

Doctors are not sure what causes GCA. A person’s genes and their exposure to things like infection may trigger the condition.

Who is affected?

GCA is more common in women. It is also more common in people with ancestors from northern Europe. It mostly affects people aged 70 years or older and is very rare in people under 50 years.

People with GCA may also experience another type of arthritis called polymyalgia rheumatica. This is a condition which causes muscle and joint stiffness, particularly in the shoulders and hips.

How is Giant Cell Arteritis diagnosed?

Doctors diagnose GCA based on the symptoms reported, a physical examination, blood tests, and a biopsy. This involves testing a small piece of tissue taken from the body. Doctors may also use scans to look inside the arteries.

Physical Examination: Your doctor will check if the area near your temple is tender to touch. They may also check if there is a weaker pulse in the artery.

Blood Tests: These are used to measure inflammation in the body. Blood tests may be repeated to monitor for changes following treatment.

Biopsy: This involves removing a small piece of tissue from in front of the ear so it can be examined under a microscope. More than one biopsy may be necessary. Sometimes, a biopsy may not confirm the diagnosis, but the doctor will recommend treatment if they strongly suspect GCA.

Scans: Ultrasound or MRI scans allow doctors to see inside arteries around the temple and armpit. Scans of the chest and stomach may be used to rule out other conditions, while a PET scan may be performed to look at the larger arteries.

What will happen to me?

The good news is that GCA can be treated. Symptoms are likely to reduce with medication. Diet changes, exercise and rest can also help.

Some people find that symptoms stop with treatment. In others, symptoms return as medication is reduced. It is important to have regular medical follow ups. Treatment may need to be increased or changed if symptoms return or become more severe.

What treatments are there for Giant Cell Arteritis?

In order to reduce the risk of blindness, treatment should begin as soon as the condition is diagnosed or suspected by your doctor.

Corticosteroids

These are the most commonly used medicine when GCA is suspected or diagnosed.

Prednisone is one of these medicines. It dampens down the immune system, which helps to reduce inflammation and lower the risk of blindness.

Doctors usually prescribe a high dose to start. The dose is then reduced over several months.

If sight is already affected, corticosteroids may be given through a drip, usually on three days in a row.

Corticosteroids can cause side-effects such as weight gain, difficulty sleeping, increased blood sugar, increased blood pressure, muscle weakness and thinning of the bones. You can find out more here.

Disease-modifying therapy

Doctors may recommend another form of medication if symptoms return or worsen.

These therapies reduce inflammation and may be used on their own or with lower doses of corticosteroids. These medicines include:

Methotrexate: This is a well-established treatment for different types of inflammatory disease. Methotrexate is taken once a week as a tablet or an injection into the muscle or under the skin.

Like all medications, methotrexate may cause side effects including fatigue, mental clouding, nausea, vomiting or diarrhea, and low white cell count that can increase the risk of mild infections. You can find out more here.

Tocilizumab: This is a newer therapy that works to target and reduce inflammation. It comes in a pre-filled syringe that is injected one a week under the skin into the fatty tissue often found in the belly or upper thigh. It is used to relieve symptoms and allow for use of corticosteroids to reduce or stop altogether.

Like all medications, tocilizumab may cause side effects including abnormal liver function, low white cell count, increase in mild infections, increase in cholesterol and in rare instances, bowel perforation. You can find out more here.

What else can I do?

It is important to learn about your condition, share feelings and seek support. There are many things you can do to help reduce symptoms and improve your health. 

Diet: A healthy diet is important, especially your intake of calcium and vitamin D.

Rich sources of calcium include:

• Dairy products
• Calcium-enriched soya milk
• Fish eaten with bones (e.g. sardines)
• Leafy green vegetables
• Beans
• Chickpeas

People with GCA should receive 1,000 milligrams (mg) of calcium each day, or 1,500 mg if they are over 60 years of age.

Good sources of Vitamin D include:

• Safe exposure to sunlight
• Oily fish (e.g. tuna and salmon)
• Supplements

It is important to eat a balanced diet and avoid over-eating.

Stay Active: Try to keep as active as possible without overdoing it. Exercise is good for your bone health. It can also help avoid weight gain and muscle weakness that may be caused by the medicine you are taking. Referral to a physiotherapist or exercise physiologist may be helpful.

Rest: Your body needs plenty of rest.

Continue treatment unless your doctor says otherwise: It can be dangerous to stop or change treatment without speaking to your doctor.

Your doctor may make changes to the corticosteroid dose you need to take. Writing the doses on a calendar may make it easier to remember when to make changes.

Regular blood tests: This will help your doctor check for inflammation and monitor for medication side effects.

Inform your doctor if symptoms return, such as headaches or changes in your vision.