The Facts
Temporal arteritis is a poorly understood but very treatable disease.
In this condition, inflammation causes medium-sized arteries to become narrow,
restricting blood flow to some organs. The arteries most commonly affected are
inside the forehead (though not in the brain). Because symptoms are felt in
the temples, it's called temporal arteritis, or sometimes cranial
arteritis. However, the same syndrome can occur in other arteries elsewhere
in the body, so it is also known as giant cell arteritis. Giant cells
are immune cells found in high concentrations inside affected arteries.
Temporal arteritis is almost unheard of in people under 50 years of age.
Among people over 50, it strikes about one person in 1000 - in the general population,
that is 3 per 10,000 people. It is at least 10 times as common in those over
80 years of age as in those between 50 and 59 years of age. Temporal arteritis
is more common in women than men. People of African descent are rarely affected.
Temporal arteritis is closely associated with a disease called polymyalgia
rheumatica, which many experts believe is a different manifestation of the
same underlying disorder. More than a 40% of people with temporal arteritis
also suffer the symptoms of polymyalgia rheumatica. Fortunately, the same treatment
is effective against both diseases.
Causes
Temporal arteritis is an autoimmune disease, in which the body's defense
system mistakenly attacks human tissue. It belongs to the same family of
diseases as rheumatoid arthritis. Most of these diseases are more common in
women. Autoimmune diseases in general are poorly understood. They tend to run
in families, but not so much that we can say they're inherited or genetic diseases.
Many doctors believe it takes a combination of predisposing genes and a "trigger"
infection, but attempts to find such infections in people with autoimmune disease
come up empty.
