Adapted from a talk at The SLE Workshop at Hospital for Special Surgery
- Warning About Misuse of the Term
- What is Vasculitis?
- What Vasculitis is Not
- When Does Vasculitis Occur in Rheumatic Disease?
- When is Vasculitis an Important Complication of an Autoimmune Disease?
- Diseases in Which Vasculitis is the Specific Illness
- Vasculitis by the Size of the Vessel
- Small Vessel Vasculitis
- Medium Vessel Vasculitis
- Large Vessel Vasculitis
Vasculitis means inflammation of the blood vessels. (Vasc refers to blood vessels and itis means inflamation). Vasculitis is a problem that can arise independently of other illness, or it may co-exist with lupus or other autoimmune diseases. When it exists in lupus, it may simply confirm the diagnosis, causing no problems, or it may represent a change in the course of the lupus, with vasculitis as a serious complication. Thus, vasculitis may mean many things. If a doctor says you have vasculitis, ask what that really means – what disease process is going on and what it means for you.
Warning About Misuse of the Term “Vasculitis” Vasculitis should not be confused with vasculopathy, which simply means something is wrong with the blood vessels, although it’s usually not vasculitis. Some people use these words interchangeably, which is wrong. Some people, even physicians and especially on the Internet, use the term “vasculitis” very loosely. So you may see statistics about vasculitis on the Internet that are very frightening, but they don’t provide any information on your situation. The term vasculitis is used ten times as often as it should be by people who are not really referring to this disease. Unfortunately, even some doctors often use the term vasculitis to mean “person with autoimmune disease and blood vessel abnormality that I don’t understand.” If your doctor says you have vasculitis, ask specifically what he/she means before you go to the Internet!
What is Vasculitis? Vasculitis is blood vessel inflammation that causes fever, pain, local tenderness, and other evidence of blocked blood vessels. When a blood vessel becomes inflamed and narrowed, blood supply to that area can become partially or completely blocked. Complete blockage is called occlusion; it causes the vessel wall to swell and makes things stick to the wall — so a clot forms. When vasculitis interferes with circulation in any part of the body, it causes local tenderness and pain. If the blood vessels are close to the skin, characteristic rashes occur. Depending on where the blockage occurs, almost any organ in the body can be affected. (Note: Vasculopathy can also block blood vessels, but it does not cause the fever, pain, and local tenderness associated with vasculitis.) While vasculitis may involve arteries (the thick muscular vessel that carries blood away from the heart) and veins (the thinner, less muscled vessels that carry blood toward the heart), it is rare for both arteries and veins to be involved at the same time.
What Vasculitis is Not Many problems that block blood vessels looks like vasculitis, and doctors often jump the gun and call them vasculitis, but greater care is needed to find out what’s really going on. Among the diseases involving blocked blood vessels that are not vasculitis: Atherosclerosis (hardening of the arteries); Growths on the heart valves that break off, especially those due to infection; Excessive blood clotting (antiphospholipid syndrome); Vessel spasm, especially due to drugs (legal and illegal).
When Does Vasculitis Occur in Rheumatic Disease? All of the rheumatic diseases involve some level of underlying vasculitis. That includes lupus, rheumatoid arthritis, scleroderma, and dermatomyositis. If you biopsy a swollen joint in RA, you routinely find vasculitis. That finding is used to confirm the diagnosis, but it doesn’t mean anything important is happening. It just suggests that one of these autoimmune diseases is present. So vasculitis is a common finding in these diseases, important in diagnosis, but it doesn’t necessarily mean anything more. It may never be a problem!
When is Vasculitis an Important Complication of an Autoimmune Disease? There are times in lupus and RA when the disease takes a different course in the presence of vasculitis. You start getting sicker and develop fever – clues to the physician that there has been a change in the course of illness. Now we say “This is lupus complicated by vasculitis” or “This is rheumatoid arthritis complicated by vasculitis.” The disease has changed its character and usually needs more vigorous treatment.