Vasculitides Health Article

Definition

Vasculitides is the plural of the word vasculitis, which may be used to describe any disorder characterized by inflammation of the blood or lymph vessels. Vasculitis is not a distinctive disease in its own right, but rather a symptom or characteristic of a number of different diseases. It can affect any type or size of blood vessel—large arteries and veins as well as arterioles, venules, or capillaries. The term juvenile vasculitides is sometimes used to refer to a group of disorders that primarily affect children and adolescents. These disorders vary widely in their severity as well as the specific blood vessels and organs affected. Some are mild and may resolve even without treatment, while others are potentially life-threatening. The most common childhood vasculitides are Kawasaki syndrome (sometimes called Kawasaki disease) and Henoch-Schönlein purpura.

The most widely used classification scheme for the vasculitides was first proposed at an international conference in 1994. It classifies these disorders according to the size of the blood vessels involved:

• Large-sized vessel vasculitis. This category includes two disorders, only one of which—Takayasu arteritis (TA)—is found in children and adolescents.
• Medium-sized vessel vasculitis. This category includes infantile polyarteritis nodosa (IPAN) and Kawasaki disease.
• Small-sized vessel vasculitis. The disorders in this category include Henoch-Schönlein purpura (HSP) and Wegener's granulomatosis.

Description

Vasculitis may damage blood vessels in two different ways. In some cases the inflamed tissue becomes weakened and stretches, producing a bulge in the wall of the vessel known as an aneurysm. The aneurysm may eventually rupture or burst, allowing blood to escape into nearby tissues. In other cases, the inflammation causes the blood vessel to narrow, sometimes to the point that blood can no longer flow through the vessel. When enough of the larger vessels supplying a specific organ or other part of the body are closed by inflammation, the tissue that is starved for blood may die. The area of dead tissue is called an infarction or infarct.

The early symptoms of vasculitis frequently include fever, weakness, loss of appetite, weight loss, tiring easily, pains in the muscles or joints, and swollen joints. Some of the childhood vasculitides affect the skin, producing rashes, ulcers, or reddish-purple spots known as purpura. Others affect the lungs, digestive tract, kidneys, liver, nervous system, eyes, or brain, resulting in symptoms ranging from pain in the abdomen, diarrhea, coughing, or high blood pressure to shortness of breath, visual disturbances, headache or fainting, and numbness in the limbs. The specific symptoms of the more common childhood vasculitides are described in more detail below.