Temporal Arteritis Health Article

Definition

Temporal arteritis is a disease that causes inflammation and sometimes blockage of medium and large arteries in the head (often near the side of the head or temples).

Description

The mechanism responsible for temporal arteritis (also called giant cell arteritis) is complex and can affect medium and large size arteries, but commonly strikes the temporal artery causing temporal located headaches. In affected arteries there is an abnormal reaction that causes the infiltration of immune cells, such as lymphocytes, multinucleated giant cells, and plasma cells. Frequently the arteries in the head and neck are involved, but vasopathy can extend to the carotids and aorta. The abnormal mechanism is a cell-mediated immune response that is abnormally directed on an antigen (a foreign protein) near the elastic tissue component of an arterial wall. This immune response causes an infiltration of immune cells in an artery which could damage or even completely block the affected blood vessel. The exact cause of temporal arteritis (TA) is unknown. TA can be serious in cases where there is involvement of blood vessels that supply blood to the affected eye (i.e., posterior ciliary artery a branch of the ophthalmic artery) which can cause visual impairment.

Demographics

The disorder is more commonly observed in persons older than 50 years. TA occurs frequently with the occurrence ranging from 10 in 100,000 to 50 in 100,000. Internationally, there seems to be a higher incidence in countries higher in northern climates. The disorder occurs more frequently in Caucasian persons of northern European descent. TA rarely occurs in Blacks and Asians and it is four to six times more frequent in women than men. The mean age of onset is 70 years and the disorder is rarely seen in persons younger than 50 years. Long term survival is the same as for the general population. Visual loss is the most worrisome complication and can occur in over 50% of persons who are untreated, which could result in blindness for 20–50% of these patients.