Takayasu's arteritis is an inflammatory disease of unknown etiology that affects the aorta and its branches. Although it has been reported worldwide, it shows a predilection for young Asian women. Females with this disease outnumber males by 8:1, and the age of onset is typically between 15 and 30 years. In the Western world, atherosclerosis is a more frequent cause of obstruction of the aortic arch vessels than is Takayasu's arteritis.
The first case of Takayasu’s arteritis was described in 1908 by Dr. Mikito Takayasu at the Annual Meeting of the Japan Ophthalmology Society. Dr. Takayasu described a peculiar "wreathlike" appearance of blood vessels in the back of the eye (retina). Two Japanese colleagues at the same meeting (Dr. Onishi and Dr. Kagoshima) reported similar eye findings in patients whose wrist pulses were absent. It is now known that the blood vessel malformations that occur in the retina are a response (new blood vessel growth) to arterial narrowings in the neck, and that the absence of pulses noted in some patients occur because of narrowings of blood vessels to the arms. The eye findings described by Takayasu are rarely seen in patients from North America.
About half of all patients develop an initial systemic illness with symptoms of malaise, fever, night sweats, weight loss, arthralgia, and fatigue. There is often an anemia and marked elevation of the ESR. This phase gradually subsides and is followed by a more chronic stage characterized by inflammatory and obliterative changes in the aorta and its branches. The other half of patients with Takayasu's arteritis present with only late vascular changes, without an antecedent systemic illness. In the late stage, weakness of the arterial walls may give rise to localized aneurysms.
Four types of late-phase Takayasu arteritis are described on the basis of the sites of involvement as follows:
Type I - Classic pulseless type that involves the brachiocephalic trunk, carotid arteries, and subclavian arteries
Type II - Combination of type I and III
Type III - Atypical coarctation type that involves the thoracic and abdominal aortas distal to the arch and its major branches
Type IV - Dilated type that involves extensive dilatation of the length of the aorta and its major branches
The great majority of patients with Takayasu’s arteritis respond to prednisone. The usual starting dose is approximately 1 milligram per kilogram of body weight per day (for most people, this is approximately 60 milligrams a day). Because of the significant side effects of long-term high–dose prednisone use, the starting dose is tapered over several weeks to a dose that the physician feels is tolerable for the patient.