Giant Cell Arteritis

temporal arteritis, GCA

Giant cell arteritis is an inflammatory disease of the blood vessels that primarily affects people over 50 years old. It can cause severe headaches, vision loss, and other serious complications if not treated quickly. With prompt treatment, most symptoms improve rapidly, though long-term medication is usually necessary.

Table of contents

• What Is Giant Cell Arteritis?
• Who Is Affected?
• What Causes Giant Cell Arteritis?
• Signs and Symptoms
• Possible Complications
• How Is It Diagnosed?
• Treatment Options
• Living With Giant Cell Arteritis

What Is Giant Cell Arteritis?

Giant cell arteritis, also known as temporal arteritis, is a condition where the lining of your blood vessels becomes inflamed^[1]. This inflammation affects large and medium-sized arteries in your body, particularly those in your head, neck, and arms^[2].

The disease gets its name from two sources. It is called “giant cell” arteritis because when doctors examine inflamed blood vessels under a microscope, they often see large or “giant” cells^[7]. The alternative name “temporal arteritis” comes from the fact that it frequently affects the temporal arteries, which run along the sides of your head near your temples^[2].

The inflammation causes your arteries to swell and narrow, which restricts blood flow^[2]. When blood flow is interrupted, it can damage vital organs and tissues. While the temporal arteries are most commonly involved, giant cell arteritis can also affect other blood vessels in the body, including the aorta (the largest artery in your body) and its major branches^[2].

• Temporal arteries
• Aorta and its branches
• Arteries of the scalp, neck, and arms
• Blood vessels supplying the optic nerve

Who Is Affected?

Giant cell arteritis almost exclusively affects people older than the age of 50^[4]. The average age when symptoms begin is around 70 years, with the disease being most common in people between 70 and 80 years old^[2].

Women develop the condition more often than men, at a rate of about two to three times more frequently^[7]. However, men who develop giant cell arteritis are more likely to experience serious complications such as blindness^[2].

The disease is more common in people of Northern European descent, particularly those of Scandinavian ancestry, and is relatively rare in people of African or Asian descent^[5]. In the United States, giant cell arteritis affects about 19 to 23 out of every 100,000 people^[2].

Giant cell arteritis is closely linked with another condition called polymyalgia rheumatica, which causes muscle stiffness and pain in the shoulders and hips. About 40 to 60 percent of people with giant cell arteritis also have polymyalgia rheumatica^[2]. Conversely, among people who have only polymyalgia rheumatica, 5 to 15 percent will eventually develop giant cell arteritis^[3].

What Causes Giant Cell Arteritis?

The exact cause of giant cell arteritis is not known^[4]. Researchers believe it is likely an autoimmune disease, meaning the body’s immune system mistakenly attacks its own healthy blood vessels^[2].

Several factors may play a role in developing the disease. Because it mainly affects older people, some experts believe it could be linked to the aging process^[5]. Genetics also appear to be important, as the disease has been associated with a specific gene variant called HLA-DRB1*04^[5]. Environmental factors that stress the immune system, such as infections, may also contribute to triggering the disease^[2].

Signs and Symptoms

The most common symptom of giant cell arteritis is a new, persistent headache that is often severe^[1]. This headache typically affects both temples and can progressively worsen, come and go, or temporarily subside^[1]. The headache is present in 40 to 90 percent of patients^[4].

Other common symptoms include:

• Scalp tenderness, often noticed when brushing or washing hair, or when sleeping on one side of the head^[1]
• Jaw pain when chewing or opening your mouth wide, particularly after eating or talking for a few minutes (called jaw claudication)^[1]
• Vision problems such as double vision, blurry vision, or temporary vision loss^[2]
• Sudden, permanent loss of vision in one eye^[1]

Many people with giant cell arteritis also experience general symptoms that may resemble the flu^[4]. These can include:

• Fatigue and generalized feeling of being unwell^[1]
• Fever^[1]
• Loss of appetite and unintentional weight loss^[1]
• Pain and stiffness in the neck, shoulders, hips, upper thighs, lower back, and buttocks^[2]

In some cases, the inflamed temporal artery may be visible or can be felt as thickened and tender when touched^[4]. Less common symptoms include pain in the ear, tongue, throat, or neck, as well as neurological symptoms such as numbness, tingling, hearing loss, or dizziness^[4].

Possible Complications

Giant cell arteritis is a serious condition that can lead to severe complications if not diagnosed and treated quickly^[2].

The most feared complication is vision loss. If untreated, vision loss occurs in 20 to 50 percent of patients^[4]. This vision loss is typically severe and almost always irreversible, even with treatment^[4]. About one-third of patients who lose vision experience temporary vision loss in one eye 7 to 10 days before permanent vision loss occurs^[4]. If not recognized and treated promptly, the second eye will lose vision within 7 to 10 days in 70 percent of cases^[4].

Other serious complications include:

• Stroke or transient ischemic attacks (temporary stroke-like symptoms, sometimes called “mini-strokes”)^[2]
• Blood vessel damage, such as an aneurysm (a widening or bulging of a blood vessel that puts it at risk of bursting)^[2]
• Heart attack in severe cases^[4]
• Kidney damage in rare instances^[4]

With proper treatment started promptly, the risk of blindness is greatly reduced. Patients who present with visual symptoms have a 22-fold increased chance of visual improvement if therapy is started within the first day^[16]. However, damage may be irreversible if treatment is delayed beyond 48 hours^[16].

How Is It Diagnosed?

Diagnosing giant cell arteritis can be difficult because its early symptoms resemble those of many other common conditions^[10]. Your doctor will start by asking about your symptoms and medical history, then perform a thorough physical examination^[10]. During the exam, the doctor will pay particular attention to your temporal arteries. Often, one or both of these arteries are tender to touch, with a reduced pulse and a hard, cord-like feel and appearance^[10].

Several tests help doctors diagnose giant cell arteritis:

Blood tests are used to detect inflammation in your body^[10]. The most common tests include:

• Erythrocyte sedimentation rate (ESR), also called “sed rate,” measures how quickly red blood cells settle to the bottom of a test tube. Red cells settle more quickly when inflammation is present^[10].
• C-reactive protein (CRP) measures a substance your liver produces when inflammation is present in your body^[10].
• Complete blood count (CBC) may show anemia (low red blood cell count)^[4].

While elevated inflammation markers are common in giant cell arteritis, these findings alone do not confirm the diagnosis, as other conditions can also cause inflammation^[3]. People with normal blood tests are much less likely to have giant cell arteritis, though there are exceptions^[4].

A temporal artery biopsy is required for definitive diagnosis^[4]. This is typically an outpatient procedure that takes less than an hour and usually does not require general anesthesia^[4]. Using a local numbing medication, the doctor removes a small segment of the temporal artery from just beneath the skin on your temple and sends it to a laboratory^[7]. Under a microscope, a specialist looks for evidence of inflammation and the presence of giant cells^[7]. The procedure is almost always safe, causes very little pain, and often leaves little or no scar^[7].

Importantly, treatment with steroids should not be delayed while waiting for a biopsy, because the biopsy can still confirm the diagnosis even after starting treatment, especially during the first week of therapy^[16]. Sometimes giant cell arteritis does not affect every part of the temporal artery but can “skip” around, so if one biopsy is negative, biopsying the artery on the other side may lead to the diagnosis^[7].

Imaging tests may also be used to diagnose giant cell arteritis and monitor response to treatment^[10]. These include:

• Ultrasound of the temporal arteries^[3]
• Magnetic resonance angiography (MRA), which produces detailed images of blood vessels^[10]
• Positron emission tomography (PET) scan, which may be recommended if your doctor suspects giant cell arteritis in large arteries such as the aorta^[10]

Treatment Options

If your doctor suspects giant cell arteritis, you will be started on high-dose steroid medication immediately, even before the diagnosis is confirmed, because of the risk of vision loss^[3]. Prompt treatment with corticosteroids usually relieves symptoms and might prevent loss of vision^[1].

The main treatment for giant cell arteritis involves two stages:

Initial high-dose treatment: Most patients are started on oral prednisone at a dose of 40 to 60 milligrams per day^[3]. Patients with visual symptoms may require even higher doses (80 to 100 milligrams per day) or may be given intravenous methylprednisolone at a dose of 1,000 milligrams daily for three days^[16]. Headaches and other symptoms often ease quickly with treatment, usually within days^[3].

Maintenance phase: After about a month of high-dose corticosteroids, the dose is gradually reduced to the lowest amount needed to control symptoms^[3]. For most patients, the prednisone dose is reduced to 5 to 10 milligrams per day over a few months^[3]. Many patients can taper off prednisone completely after one to two years, though some may need to continue treatment longer^[3]. The disease can return after treatment stops^[3].

In May 2017, a medication called tocilizumab was approved for the treatment of giant cell arteritis^[3]. This drug is given by intravenous infusion or subcutaneous injection and helps decrease the need for corticosteroids^[3].

Your doctor may also prescribe additional medications to prevent side effects or complications:

• Low-dose aspirin (81 milligrams) to reduce the risk of vision loss and stroke^[16]
• Proton pump inhibitors to lower the risk of stomach problems like indigestion or stomach ulcers, which can be side effects of taking prednisone^[9]
• Vitamin D, calcium, or bisphosphonates to reduce the risk of osteoporosis (bone thinning) when taking prednisone^[9]

Corticosteroids can cause side effects, which are more common with higher doses^[3]. These may include changes in mood, weight gain, poor sleep, muscle weakness, cataracts (clouding of the eye lens), and skin bruising^[3]. Most steroid side effects are temporary and can be managed^[3]. Your doctor may want you to get a bone density test and will suggest ways to prevent osteoporosis and bone fractures^[3].

You will need regular follow-up visits with your doctor to monitor your response to treatment and check for any side effects^[1]. Both clinical signs and measurements of inflammation markers in your blood (ESR or CRP) help monitor your response to treatment^[16].

Living With Giant Cell Arteritis

Managing giant cell arteritis requires long-term commitment to treatment and lifestyle adjustments. With appropriate therapy, the disease is treatable, controllable, and often curable^[7].

Small lifestyle changes can help you manage your condition:

• Focus on eating plenty of fresh fruits, vegetables, whole grains, and lean meats and fish^[17]
• Ask your healthcare professional about planning an exercise program that is comfortable for you^[17]
• Keep track of new or worsening symptoms and bring questions to your medical appointments^[17]
• Dedicate time every day to do something you enjoy to help reduce stress^[17]

It is important to attend all scheduled follow-up appointments. Once symptoms disappear and inflammatory markers in your blood return to normal, the risk of blindness is greatly reduced^[5]. However, you should remain alert to any new symptoms and report them promptly to your doctor.

If you have polymyalgia rheumatica along with giant cell arteritis, report any symptoms of new headache, changes in vision, or jaw pain to your doctor immediately^[3]. These could be signs that the disease is becoming more active.

Even with prompt treatment, vision loss may be permanent if it has already occurred^[16]. However, treatment can prevent further deterioration and protect the other eye. Patients with multi-infarct complications should not expect immediate recovery, but longitudinal follow-up should show no further deterioration and may show modest improvement^[16].

Talking to family and friends about your condition can help them understand what you are going through. You might explain that some of your blood vessels are inflamed, which can cause intense headaches, joint stiffness, and unusual tiredness, so you may not be able to do all the things you normally would^[17]. Consider searching for support groups where you can connect with others going through similar experiences^[17].