What is temporal arteritis?
Temporal arteritis is a form of vasculitis (inflammation of the blood vessels). In temporal arteritis, also known as giant cell arteritis or Horton's arteritis, the temporal arteries (the blood vessels near the temples), which supply blood from the heart to the scalp, are inflamed (swollen) and constricted (narrowed). The vasculitis that causes temporal arteritis can involve other blood vessels, such as the posterior ciliary arteries (leading to blindness), or large blood vessels like the aorta and its branches, which can also lead to serious health problems.
If not diagnosed and treated quickly, temporal arteritis can cause:
- Damage to eyesight, including sudden blindness in one or both eyes.
- Damage to blood vessels, such as an aneurysm (a ballooning blood vessel that may burst).
- Other disorders, including stroke or transient ischemic attacks (“mini-strokes”).
How common is temporal arteritis?
Temporal arteritis is one of the most common vascular disorders, but is a relatively rare condition, affecting about 5 out of 10,000 people. It usually occurs in people who are over 50 years old, and affects women more often than men.
Symptoms and Causes
What are the symptoms of temporal arteritis?
The most common symptom of temporal arteritis is a throbbing, continuous headache on one or both sides of the forehead. Other symptoms may include:
- Jaw pain that may become worse after chewing
- Tenderness at the scalp or temples
- Vision problems, such as double vision, blurry vision, or transient (brief) vision loss; if this is not treated, it could be followed by permanent, irreversible vision loss
- Muscle aches in the upper arms or shoulders, hips, upper thighs, lower back, and buttocks
- Loss of appetite or weight loss
Often, temporal arteritis can be associated with an entity called polymyalgia rheumatica (PMR), which is an inflammatory condition affecting the shoulders, hip girdle and neck. This leads to significant stiffness and pain. PMR is far more common than temporal arteritis, but up to 30 percent of temporal arteritis patients have PMR.
What causes temporal arteritis?
The causes of temporal arteritis are poorly understood. There is no well-established trigger or risk factors.
One cause may be a faulty immune response; i.e., the body's immune system may “attack” the body. Temporal arteritis often occurs in people who have polymyalgia rheumatica.
Diagnosis and Tests
How is temporal arteritis diagnosed?
The patient history is very important and will make the doctor consider the diagnosis. The doctor will perform a physical examination and will check to see whether the patient's pulse is weak. The doctor will also examine the patient's head to look for scalp tenderness or swelling of the temporal arteries.
The doctor will first order blood tests, such as erythrocyte sedimentation rate and C-reactive protein, to measure how much inflammation (swelling) there is in the body. The doctor will also test for anemia by measuring the hemoglobin level (the part of red blood cells that carries oxygen).
If temporal arteritis is suspected, the doctor may order a biopsy, in which a small piece of the artery is removed and examined for evidence of inflammation within the vessels.
Other tests that are sometimes necessary include:
- Magnetic resonance imaging (MRI), which uses a large magnet, radio waves, and a computer to produce sharp pictures of the body;
- Positron emission tomography (PET) scan, in which a very small dose of a radioactive chemical is injected into the vein of the arm so that it can be followed on a PET scanner via three-dimensional pictures;
- Ultrasound, which sends high-frequency sound waves through body tissues. The echoes are recorded and turned into photos of the inside of the body.
Management and Treatment
How is temporal arteritis treated?
Although there is no cure for temporal arteritis, the condition can be treated with medications. Temporal arteritis should be treated as soon as possible to prevent further damage caused by poor blood flow. Patients over the age of 50 who have the following symptoms should contact a doctor immediately:
- New onset headache
- Sudden and brief loss of vision
- Jaw pain with or after chewing food or after talking.
The mainstay of therapy for temporal arteritis is glucocorticoids, such as oral prednisone. Patients sometimes need to take glucorticoids for up to two years, sometimes longer; the dosage is gradually reduced over this period.
Since there are serious side effects associated with the long-term use of corticosteroids, patients have to be watched carefully while taking these drugs. Side effects include a greater chance of fractures (because steroids can make the bones thinner), and infections (because steroids suppress the immune system).
Tests that measure the thickness of bones, such as bone mineral density tests or DEXA scans, can detect osteoporosis (thinning of the bones). The doctor may recommend supplements such as calcium and vitamin D, and exercises such as walking or weight-bearing exercises, to prevent osteoporosis.
Fortunately, a new medication called tocilizumab was approved by the Food and Drug Administration in 2017 to treat temporal arteritis. This medication is given as a subcutaneous injection.
The patient should not smoke, and alcohol should be kept to a minimum.
Outlook / Prognosis
What is the outlook for patients with temporal arteritis?
The outlook for those with temporal arteritis is very good, unless the person has had a loss of vision. If that occurs, the damage generally cannot be reversed. Most complications associated with temporal arteritis are from the use of steroid drugs, not from the disease itself.