Vasculitis refers to a varied group of disorders which all share a common underlying problem of inflammation of a blood vessel or blood vessels. The inflammation may affect any size blood vessel, anywhere in the body. It may affect either arteries and/or veins. The inflammation may be focal, meaning that it affects a single location within a vessel; or it may be widespread, with areas of inflammation scattered throughout a particular organ or tissue, or even affecting more than one organ system in the body.
Inflammation is a process which occurs when the immune system of the body responds to either an injury or a foreign invader (virus, bacteria, or fungi). The immune system response involves sending a variety of cells and chemicals to the area in question. Inflammation causes blood vessels in the area to leak, causing swelling. The inflamed area becomes red, hot to the touch, and tender.
Antibodies are immune cells which recognize and bind to specific markers (called antigens) on other cells (including bacteria and viruses). These antibody-antigen complexes can then stimulate the immune system to send a variety of other cells and chemicals involved in inflammation to their specific location.
Some researchers believe that the damaging process of vasculitis is kicked off by such antibody-antigen complexes. These complexes are deposited along the walls of the blood vessels. The resulting inflow of immune cells and chemicals causes inflammation within the blood vessels.
The type of disease caused by vasculitis varies depending on a number of factors:
- the organ system or tissue in which the vasculitis occurs
- the specific type of inflammatory response provoked
- whether the affected vessels are veins (which bring blood to the heart) or arteries (which carry blood and oxygen from the heart to the organs and tissues)
- the degree to which blood flow within the affected vessel is reduced
Causes and symptoms
Some types of vasculitis appear to be due to a type of allergic response to a specific substance (for example, a drug). Other types of vasculitis have no identifiable initiating event. Furthermore, researchers have not been able to consistently identify antibody-antigen complexes in all of the types of diseases caused by vasculitis. The types of antigens responsible for the initial immune response have often gone unidentified as well. Furthermore, not all people with such complexes deposited along the blood vessels go on to develop vasculitis. Some researchers believe that, in addition to the presence of immune complexes, an individual must have some other characteristics which make him or her susceptible to vasculitis. Many questions have yet to be answered to totally explain the development these diseases.
Symptoms of vasculitis depend on the severity of the inflammation and the organ system or systems affected. Some types of vasculitis are so mild that the only symptoms noted are small reddish-purple dots (called petechiae) on the skin due to tiny amounts of blood seeping out of leaky blood vessels. In more widespread types of vasculitis, the patient may have general symptoms of illness, including fever
, achy muscles and joints, decreased appetite, weight loss, and loss of energy. The organ systems affected by vasculitis may include:
- The skin. Rashes, bumps under the skin, petechiae, larger reddish-purple circles (purpura), or bruising (ecchymoses) may appear. Areas of skin totally deprived of blood flow, and therefore of oxygen, may die, resulting in blackened areas of gangrene.
- The joints. In addition to joint pain, the joints themselves may become inflamed, resulting in arthritis.
- Brain and nervous system. Inflammation of the blood vessels in the brain can cause headaches, changes in personality, confusion, and seizures. If an area of the brain becomes totally deprived of oxygen, a stroke occurs. A stroke means that an area of brain tissue is either severely injured or completely dead from lack of oxygen. This may leave the individual with a permanent disability. If the vessels that lead to the eyes are affected, vision may become seriously disturbed. Nerves in the arms and legs may result in painful tingling sensations, loss of feeling, and weakness.
- Gastrointestinal system. Patients may have significant abdominal pain, vomiting, and diarrhea. If blood flow is completely cut off to an area of intestine, that part of the intestine will die off. The liver may be affected.
- Heart. This is an extremely serious type of vasculitis. The arteries of the heart (coronary arteries) may develop weakened areas, called aneurysms. The heart muscle itself may become inflamed and enlarged. With oxygen deprivation of the heart muscle, the individual may suffer a heart attack.
- Lungs. The patient may experience shortness of breath with chest pain, and may cough up blood. There may be wheezing.
- Kidney. Changes in the arteries of the kidney may result in high blood pressure. The kidneys may become increasingly unable to appropriately filter the blood, and kidney failure may occur.
Multiple types of disease are associated with vasculitis. Many autoimmune diseases have vasculitis as one of their complications. These include systemic lupus erythematosus, rheumatoid arthritis
, scleroderma, and polymyositis
. Other types of diseases which have vasculitis as their major manifestations include:
- Polyarteritis nodosa. This is an extremely serious, systemic (affecting systems throughout the body) form of vasculitis. Small and medium arteries are involved, and the inflammation is so severe that the walls of the arteries may be destroyed. Any organ system, or multiple organ systems, may be affected. The most serious effects include kidney failure, complications involving the heart, gastrointestinal problems, and high blood pressure.
- Kawasaki's disease is an acute disease which primarily strikes young children. Fever and skin manifestations occur in all patients. While most patients recover completely, a few patients suffer from vasculitis in the heart. This is frequently fatal.
- Henoch-Schonlein purpura. While this frequently occurs in children, adults may also be affected. This disease tends to affect the skin, joints, gastrointestinal tract, and kidneys.
- Serum sickness occurs when an individual reacts to a component of a drug, for example penicillin. Symptoms of this are often confined to the skin, although fevers, joint pain, and swelling of lymph nodes may also occur.
- Temporal arteritis (also called giant cell arteritis) tends to involve arteries which branch off the major artery that leads to the head, called the carotid. An artery which feeds tissues in the area of the temple (the temporal artery) is often affected. Severe headaches are the most classic symptom. Other symptoms include fatigue, loss of appetite and then weight, fever, heavy sweating, joint pain, and pain in the muscles of the neck, shoulders, and back. If the vasculitis includes arteries which supply the eye, serious visual disturbance or even blindness may result.
- Takayasu's arteritis affects the aorta (the very large main artery that exits the heart and receives all of the blood to be delivered throughout the body), and arteries which branch off of the aorta. Initial symptoms include fatigue, fever, sweating at night, joint pain, and loss of appetite and weight. Every organ may be affected by this disease. A common sign of this disease is the inability to feel the pulse in any of the usual locations (the pulse is the regular, rhythmic sensation one can feel with a finger over an artery, for example in the wrist, which represents the beating of the heart and the regular flow of blood).
- Wegener's granulomatosis: This disease exerts its most serious effects on the respiratory tract. The vasculitis produced by this disease includes the formation of fibrous, scarring nodules called granulomas. Symptoms include nose bleeds, ear infections, cough, shortness of breath, and chest pain. There may be bleeding in the lungs, and a patient may cough up blood. The kidneys, eyes, and skin are also frequently involved.
Diagnosis of any type of vasculitis involves demonstrating the presence of a strong inflammatory process. Tests which reveal inflammation throughout the body include erythrocyte sedimentation rate
, blood tests which may reveal anemia and increased white blood cells, and tests to demonstrate the presence of immune complexes and/or antibodies circulating in the blood. An x-ray procedure, called angiography
, involves injecting dye into a major artery, and then taking x-ray pictures to examine the blood vessels, in order to demonstrate the presence of inflammation of the vessel walls. Tissue samples (biopsies) may be taken from affected organs to demonstrate inflammation.
— A weakened area in the wall of a blood vessel which causes an outpouching or bulge. Aneurysms may be fatal if these weak areas burst, resulting in uncontrollable bleeding.
— Specialized cells of the immune system which can recognize organisms that invade the body (such as bacteria, viruses, and fungi). The antibodies are then able to set off a complex chain of events designed to kill these foreign invaders.
— A special, identifying marker on the outside of cells.
— A disorder in which the body's antibodies mistake the body's own tissues for foreign invaders. The immune system therefore attacks and causes damage to these tissues.
— The system of specialized organs, lymph nodes, and blood cells throughout the body which work together to prevent foreign invaders (bacteria, viruses, fungi, etc.) from taking hold and growing.
— The body's response to tissue damage. Includes hotness, swelling, redness, and pain in the affected part.
— A tiny, purplish-red spot on the skin. Caused by the leakage of a bit of blood out of a vessel and under the skin.
— A large, purplish-red circle on the skin. Caused by the leakage of blood out of a vessel and under the skin.
Even though there are many different types of vasculitis, with many different symptoms based on the organ system affected, treatments are essentially the same. They all involve trying to decrease the activity of the immune system. Steroid medications (like prednisone) are usually the first types of drugs used. Steroids work by interfering with the chemicals involved in the inflammatory process. More potent drugs for severe cases of vasculitis have more serious side effects. These include drugs like cyclophosphamide. Cyclophosphamide works by actually killing cells of the patient's immune system.
The prognosis for vasculitis is quite variable. Some mild forms of vasculitis, such as those brought on by reactions to medications, may resolve totally on their own and not even require treatment. Temporal arteritis, serum sickness, Henoch-Schonlein purpura, and Kawasaki's disease usually have excellent prognoses, although when Kawasaki's affects the heart, there is a high death rate. Other types of vasculitis were always fatal, prior to the availability of prednisone and cyclophosphamide, and continue to have high rates of fatal complications. These include polyarteritis nodosa and Wegener's granulomatosis.
Because so little is known about what causes a particular individual to develop vasculitis, there are no known ways to prevent it.
Lupus Foundation of America. 1300 Piccard Dr., Suite 200, Rockville, MD 20850. (800) 558-0121. http://www.lupus.org.
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Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.
hypersensitivity vasculitis a group of systemic necrotizing vasculitides thought to represent hypersensitivity to an antigenic stimulus, such as a drug, infectious agent, or exogenous or endogenous protein; all disorders in this group involve the small vessels.
nodular vasculitis a chronic vasculitis of unknown etiology found predominantly below the knees, especially on the calves in young and middle-aged women, characterized by the presence of painful, reddish blue nodular lesions that may ulcerate, leaving scars, or resorb, leaving atrophic depressions. In the late stages, there is replacement of the subcutaneous fat by fibrosis and atrophy (wucher atrophy).
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.
vasculitis (vas?kyu-lit'is) (-lit'i-dez?) plural.vasculitides [L. vasculum, small vessel + -itis]
Inflammation of blood vessels. Synonym: angiitis
It is usually caused by deposition of antigen-antibody immune complexes or other immune-mediated events. Vasculitis due to immune complexes is seen in patients with systemic lupus erythematosus, rheumatoid arthritis, hepatitis B and C, serum sickness, and drug reactions. Vasculitis found in patients with inflammatory bowel disease, Wegener granulomatosis, graft rejection, polyarthritis nodosa, and temporal arteritis involves other immune-mediated processes. Vasculitis often affects the renal glomeruli, joints, cerebral vessels, testes, or respiratory system.
Vasculitis can affect large, medium-sized, and small blood vessels. When it is found in small blood vessels in the skin, characteristic rashes may be seen. Vasculitis is loosely classified by the size of the vessel involved. Takayasu and giant cell arteritis involve large arteries, including the aorta and carotids. Polyarteritis nodosa and Kawasaki disease involve medium-sized vessels; Wegener granulomatosis, Henoch-Schönlein purpura, and microscopic polyangiitis involve small vessels, particularly in the kidney and respiratory tract. See: illustration; autoimmune disease; immune complex
Although fever, pain, and malaise are common, the inflammatory changes of the blood vessels are seen primarily through the signs and symptoms associated with the organ or tissues involved. Vasculitis in superficial vessels may present as painful nodules. Inflammation of the glomerular capillaries of the kidney in small vessel vasculitis may produce glomerulonephritis and decreased renal function. When blood vessels of the respiratory tract are involved, pneumonitis, sinusitis, and ulceration of the nasopharynx may result. Involvement of vessels in the heart leads to coronary artery disease and aneurysms.
Immunosuppressive therapy (with drugs such as cyclophosphamide and prednisone, or monoclonal antibodies such as rituximab) is used to treat most forms of autoimmune-mediated vasculitis.
A vasculitis with bloodclotting that affects small blood vessels in the skin, esp. near the feet and ankles. The cause in most cases is unknown, but it may be associated with diseases such as antiphospholipid antibody syndrome, systemic lupus erythematosus or scleroderma. illustration
The inflammation that occurs when antigen-antibody complexes are deposited on the walls of small blood vessels in transplanted organs. Although the transplant rejection process is dominated by T-cell–mediated activities, antibodies also may form against the histocompatibility antigens on the transplanted organ and compromise its viability. See: major histocompatibility complex
A relatively rare complication of severe rheumatoid arthritis, characterized by blood vessel inflammation, esp. in the skin, eyes (the sclera), and nerves. It can produce deep dermal ulcers, localized skin infarction, ischemia or necrosis of the fingertips, scleritis, and inflammation of multiple nerves (mononeuritis multiplex).
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