The vascular system refers to the collection of all blood vessels in the body. Vasculitis is the term used for a group of diseases characterized by theinflammation of and damage to the blood vessels or the blood vessel walls. Vasculitis (plural vasculitides) can be a primary disease or a secondary condition related to another underlying disease.
Different types of vasculitis have certain patterns of distribution that may affect particular organs, certain types of vessels, or specific vessel sizes. Vasculitis diseases affecting arteries are sometimes called arteritis and those involving the veins are sometimes called venulitis. Overall, vasculitides (all types of vasculitis or vasculitic disorders) are uncommon conditions.
In general terms, blood vessels can be divided into arteries, veins and capillaries:
- Arteries are the blood vessels carrying oxygenated blood from the lungs away from the heart to different organs.
- Veins are blood vessels collecting the blood without oxygen from the body organs to carry back to heart to be pumped to the lungs where it receives oxygen.
- The largest artery is the aorta coming out of the left side of the heart. The aorta divides into many smaller branches as it passes through the body, thus giving rise to arteries of different sizes. The small arteries (arterioles) then branch further into capillaries, which are very small blood vessels distributed diffusely within all organs of the body. The exchange of oxygen and waste products between the blood vessels and tissues happens at the level of the capillaries.
These small blood vessels then coalesce to form small veins (venules) which give rise to larger and larger veins that eventually end up in the right side of the heart via the body's largest vein, the vena cava.
The signs and symptoms of vasculitis can be very vague, generalized, and non-specific. This is because of the complexity and variability of the different types of vasculitic diseases. It is also important to realize that vasculitis, as a whole, is a rare condition compared to other common conditions that may also cause similar signs and symptoms.
It may be safe to say that most of the signs and symptoms related to vasculitis are caused because the inflammation of the blood vessels results in impaired or complete lack of blood flow to the specific organ(s) supplied by the affected blood vessels.
- CNS vasculitis may cause headaches, confusion, or focal neurologic problems.
- Churg-Strauss vasculitis can have symptoms similar to asthma because of its involvement of the lungs.
- Henoch-Schonlein purpura can present as purpura (small raised purple areas under the skin due to hemorrhage), abdominal pain or nausea and vomiting, joint pain, or blood in the urine (hematuria) because of its systemic involvement.
- Temporal arteritis may present as a headache and tender, thick blood vessels on the side of the fore head.
- Cutaneous vasculitis may cause purpura, urticaria (hives), or ulcers of the skin.
The actual cause of these vasculitis diseases is usually not known. However, immune systemabnormality and inflammation of blood vessels are common features. Each form of vasculitis has its own characteristic pattern of symptoms, much of which depends on what particular organs are affected.
Examples of vasculitis include Kawasaki disease, Behcet's disease, polyarteritis nodosa, Wegener's granulomatosis, cryoglobulinemia, Takayasu's arteritis, Churg-Strauss syndrome, giant cell arteritis (temporal arteritis), and Henoch-Schönlein purpura.
Vasculitis can also accompany infections (such as hepatitis B), exposure to chemicals (such as amphetamines and cocaine), medications, cancers (such as lymphomas and multiple myeloma), and rheumatic diseases (such asrheumatoid arthritis and systemic lupus erythematosus).
The treatment of the various forms of vasculitis is based on the severity of the illness and the organs involved. Treatments are generally directed toward stopping the inflammation and suppressing the immune system. Typically, cortisone-related medications, such as prednisone, are used.
Additionally, other immune suppression drugs, such as cyclophosphamide (Cytoxan) and others, are considered. Additionally, affected organs (such as the heart or lungs) may require specific medical treatment when the disease is active.
The management of vasculitis is an evolving field in medicine. The ideal programs for monitoring and treatment will continue to improve as disease patterns and causes are defined by medical research.