IMMUNE THROMBOCYTOPENIC PURPURA
What is Immune Thrombocytopenic Purpura?
Immune Thrombocytopenic Purpura (ITP) is a disorder of the blood.
Immune refers to the immune system's involvement in this disorder. Antibodies, part of the body's immunological defense against infection, attach to blood platelets, cells that help stop bleeding, and cause their destruction. Thrombocytopenia refers to decrease in blood platelet. Purpura refers to the purplish-looking areas of the skin and mucous membranes (such as the lining of the mouth) where bleeding has occurred as a result of decreased platelet.
What Causes Immune Thrombocytopenic Purpura?
Some cases of ITP are caused by drugs, and others are associated with infection, pregnancy, or immune disorders such as systemic lupus erythematosus. About half of all cases are classified as "idiopathic," meaning the cause is unknown.
What are the Symptoms of Immune Thrombocytopenic Purpura?
The main symptom is bleeding which can include bruising ("ecchymosis") and tiny red dots on the skin or mucous membranes ("petechiae"). In some instances bleeding from the nose, gums, digestive or urinary tracts may also occur. Rarely, bleeding within the brain occurs.
How is Immune Thrombocytopenic Purpura Diagnosed?
The physician will take a medical history and perform a thorough physical examination. A careful review of medications the patient is taking is important because some drugs can be associated with thrombocytopenia. A complete blood count will be done. A low platelet count will establish thrombocytopenia as the cause of purpura. Often the next procedure is a bone marrow examination to verify that there are adequate platelet-forming cells (megakaryocyte) in the marrow and to rule out other diseases such as metastatic cancer (cancer that has spread to the bone marrow) and leukemia cancer of the blood cells themselves). Another blood sample may be drawn to check for other conditions sometimes associated with thrombocytopenia such as lupus and infection.
How is Immune Thrombocytopenic Purpura Treated?
If the doctor thinks a drug is the cause of the thrombocytopenia, standard treatment involves discontinuing the drug's use. Infection, if present, is treated vigorously since control of the infection may result in a return of the platelet count to normal.
The treatment of idiopathic thrombocytopenic purpura is determined by the severity of the symptoms. In some cases, no therapy is needed. In most cases, drugs that alter the immune system's attack on the platelet are prescribed. These include corticosteroids (i.e., prednisone) and/or intravenous infusions of immune globulin.
Another treatment that usually results in an increased number of platelet is removal of the spleen, the organ that destroys antibody-coated platelet. Other drugs such as vincristine, azathioprine (Imuran), Danazol, cyclophosphamide, and cyclosporine are prescribed for patients only in the severe case where other treatments have not shown benefit since these drugs have potentially harmful side effects.
Excepts in certain situation (e.g., internal bleeding and preparation for surgery), platelet transfusion usually are not beneficial and, therefore, are seldom performed. Because all therapies can have risks, it is important that overtreatment (treatment based solely on platelet counts and not on symptoms) be avoided.
In some instances lifestyle adjustments may be helpful for prevention of bleeding due to injury. These would include use of protective gear such as helmets and avoidance of contact sports in symptomatic patients or when platelet counts are less than 50,000. Otherwise, patients usually can carry on normal activities, but final decisions about activity should be madein consultation with the patient's hematologist.
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