Vasculitis is a general term that refers to inflammation of blood vessels. When blood vessels become inflamed, they may become weakened, stretch, and either increase in size or become narrow -- even to the point of closing entirely.
Vasculitis can affect people of all ages, but there are types of vasculitis that occur in certain age groups more often than others.
Some of the many forms of vasculitis may be restricted to particular organs. Examples include vasculitis that affects only the skin, eye, brain, or certain internal organs. There are also types of vasculitis that may affect many organ systems at the same time. Some of these generalized forms may be quite mild and may not require treatment. Others may be severe, affecting critical organs.
In many cases, the cause of vasculitis is unknown. In a few cases, however, the origins may be traced to recent or ongoing infections, such as those caused by certain viruses. Occasionally, an allergic reaction to a medication may trigger vasculitis.
Vasculitis can sometimes develop after an infection has come and gone. Usually in these cases, the infection triggers an abnormal response in the person's immune system, damaging the blood vessels. Vasculitis also may be related to other diseases of the immune system that the person has had for months or years. For example, it could be a complication of rheumatoid arthritis, lupus, or Sjögren's syndrome.
How Serious Is Vasculitis?
Vasculitis can be very serious. In an extreme situation, when a segment of a blood vessel becomes weakened, it may then stretch and bulge (called an aneurysm). The wall of the blood vessel can become so weak that it ruptures and bleeds, possibly causing death. Fortunately, this is a very rare event.
If a blood vessel becomes inflamed and narrowed, the blood supply to the area of the body it serves may be partially or completely blocked. If alternate blood vessels (called collateral blood vessels) are not available in sufficient quantity to carry the blood to such sites, the tissue supplied by the affected vessels will die. Because vasculitis can occur in any part of the body, any tissue or organ can be affected.