Temporal arteritis, now called giant cell arteritis, is a type of vasculitis, or inflammation of the blood vessels. It involves a swelling and thickening of the artery lining on the temple, or side of the head, under the skin.
It is an autoimmune condition that arises when the immune system is attacking healthy cells by accident due to a faulty immune system reaction.
It is now called giant cell arteritis (GCA), as research has shown that not just the temporal arteries can be affected. Other blood vessels that may develop GCA include in the head and neck, the thoracic aorta and its branches.
The term “giant cell” is used because it shows enlarged cells by biopsies of inflamed temporal arteries, seen under a microscope.
GCA is known at least since the 10th century. Other names include horton disease and cranial arteritis.
Symptoms include persisting headache. This can lead to permanent loss of vision without treatment.
After age 50, GCA is the most popular. With age it raises the chances of developing it. It affects about 18 people every 100,00 a year, and when a person is in their 80s it is most likely to occur.
Females are two or three times more likely to be affected than men.
Symptoms
The key symptom is a serious, persistent, and possibly throbbing headache, usually on either side of the head or front.
Two of the three people suffering from this disorder will have headache.
Further symptoms include:
- tender temples
- mouth-related pain, especially affecting the jaw, that may be felt when eating
- pain in the tongue, throat, or face
- pain or swelling on top of the head, or scalp
- blurry or double vision
A flu-like feeling that affects one in three people with GCA with a loss of appetite , weight loss, sweating, fever and malaise.
Anyone experiencing those symptoms should see a diagnostic and treatment doctor. If problems with the vision arise, immediate medical assistance is needed.
Complications
The most significant potential condition is vision loss, which can occur all of a sudden and be permanent.
It may occur if the vasculitis affects an eye-supplying artery and causes damage to the optic nerve.
Signs of visual impairment include:
- blurred or double vision
- blind spots
- drooping eyelid
Total and permanent vision loss can be accompanied by brief periods of total vision loss in one eye.
Vision loss affects people with GCA between 14 and 20 percent. Before corticosteroids were introduced, the rate was 30 to 60 percent.
If treatment for GCA begins before any effect on vision, the risk of later occurring blindness will be reduced to 1 percent or less.
- Fifty-eight percent experience visual improvements if treatment is started within 24 hours
- Six percent experience improvements if treatment starts “after a delay.”
Monitoring and retaining vision in the unaffected eye is also important.
In 50 per cent of people with a GCA diagnosis, visual loss affects the other eye within days to weeks.
Other complications are less common , for example severe swelling of the arteries. GCA was also linked to a higher risk of a heart attack, stroke or aortic aneurysm, however.
Diagnosis
It ‘s important to see a physician with any symptoms that might indicate GCA.
A doctor will take into account the symptoms described by the patient, ask questions and explore other possibilities. Often, they must do a physical exam.
If GCA is a possibility, treatment should start right away.
Tests which can be used to diagnose the condition include:
- blood tests to assess for erythrocyte sedimentation rate
- ultrasound to check for abnormalities in the temporal arteries
- a biopsy of the artery wall, carried out under local anesthetic, to assess for inflammation of the artery
Treatment may begin before the biopsy results, due to the risk of loss of vision.
Causes
GCA affects temporal arteries and may also develop within the thoracic artery.
Every side of the head has one temporal artery.
Each runs above and around the part of the skull that is above the ear. Both arteries run up in front of the ear themselves. From the two main supplies of blood they branch out from the heart to the head.
The exact cause of GCA is unknown but it is believed to be an autoimmune condition in which the immune system of the body attacks healthy cells in the arteries. That results in inflammation.
When the lining of the blood vessel becomes inflamed, giant lesions in the cells may develop.
When numerous immune cells fuse together these giant cells form. Those immune cells are a white blood cell type.
Giant cells also play a role in tuberculosis ( TB), leprosy, some fungal infections, and other conditions.
Risk factors
It isn’t fully understood why some people develop temporal arteritis. It’s still unclear why other people are at greater risk than others.
Age is a factor in the risk. The average age GCA starts at is 70 years.
Other possible factors may include:
- geographical location
- seasonal factors
- genetic factors
- exposure to viruses or toxins
- having other health conditions related to vasculitis or inflammation
GCA and polymyalgia rheumatica
Polymyalgia rheumatica (PMR) is an inflammatory form which affects the entire body. Symptoms include stiffness and pain, especially in the neck , shoulders, upper arms, and around the pelvis.
Like with GCA, it is also more common in people over the age of 55 and affects more women than men.
According to Arthritis Research UK, about 15 % of people with rheumatic polymyalgia (PMR) also have temporal arteritis, and about 40 to 60 % of people with temporal arteritis also have PMR.
GCA and systemic vasculitis
Systemic vasculitis is associated with temporal arteritis, because one form of vasculitis is the inflammation of cranial arteries.
Systemic vasculitis refers to a range of disorders involving inflammation and damage to the walls of the blood vessels that can result in tissue death.
The various types are classified and managed according to the size of the affected blood vessel — large , medium, or small — and the area of effect, such as on an organ.
The affected arteries are medium with temporal arteritis, and risk to the eye.
The treatment approach with glucocorticosteroids for both systemic vasculitis and GCA is.
Why is temporal arteritis more common in Minnesota?
People with a background in northern Europe show a higher risk of developing temporal arteritis. The exact reason for that is unclear.
One study into rates of temporal arteritis in the United States looked at where the population is largely made up of that ethnic background: Minnesota.
In particular the researchers researching Olmsted County found that the prevalence here was as high as in Sweden, a country with one of the highest levels of temporal arteritis.
Over a period of 50 years , the study found that, during that time, there were almost 20 cases of people for every 100,000. The number of cases is small in the Mediterranean region. For every 100,000 people there are 6.9 cases in northern Italy, where temporal arteritis is at its lowest.
The authors wrote that the divide between the north and the south might be due to environmental, genetic or ethnic factors.
However, in the general population average rates of temporal arteritis are relatively low, although they are more common in older people.
Treatment
Treatment will usually start at once to reduce the risk of complications, likely before the biopsy results are confirmed. The person may need to see a medical specialist.
High-dose corticosteroid medications have been the standard treatment since the 1950s, but a further medication has been approved recently: Actemra.
Corticosteroids
These guard against risks such as vision loss. The recommendation is to “immediately and aggressively” initiate these.
The dose usually for about a month is 40 to 60 milligrams ( mg) of prednisone (such as Orasone or Deltasone) each day. Symptoms will improve rapidly upon start of treatment.
People with visual symptoms will get the greater dose.
After a month the dose gradually decreases. Eventually, during several months, a person may take 5 to 10 mg daily.
Treatment must begin rapidly to avoid vision loss.
More than half of all people receiving GCA corticosteroids would experience side effects.
Actemra (tocilizumab)
Another drug, Actemra (tocilizumab), received Food and Drug Administration ( FDA ) approval for treatment of this condition in 2017.
It is administered by injection. Actemra is an antagonist of the receptor interleukin-6 ( IL-6), also used for the treatment of rheumatoid arthritis. It affects the immune system.
Side effects include:
- stomach tears
- changes in blood composition
- a higher risk of some cancers
- possible allergic reactions
- nervous system complications
Anyone who experiences the following after using this drug should see their doctor:
- upper respiratory tract infections
- headaches
- high blood pressure
- a reaction at the injection site
A doctor may prescribe aspirin to help prevent blood clots, unless the person has another condition, such as a stomach ulcer or bleeding disorder, that does not allow that.
Outlook
The outlook is poor without medication but with modern medicine, GCA symptoms typically improve within days of beginning treatment, and vision loss is now uncommon.
The time required for a full recovery, however, can vary greatly. The average treatment period is 2 years but care can extend for 5 years or longer for certain cases.
Those who have GCA are also more likely to have an aortic aneurysm and a cardiovascular disease.
In addition, long-term steroid use can result to some health issues.
Research do not say a person with GCA is more likely to die earlier than a person without the condition. However, it is important to attend all follow-up appointments to ensure that treatment for any complications is received in good time.
