Immune Thrombocytopenic Purpura
by Erica Lindquist

Immune Thrombocytopenic Purpura, or simply ITP, is a blood disorder. The “immune” part of the name refers to the immune system's involvement in this disorder. Antibodies, part of the body's immunologic defense against infection, attach to blood platelets, cells that dissolve to help clot blood and stop bleeding, and cause their destruction. “Thrombocytopenic” is talking about the decrease in blood platelet. “Purpura” is a 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 platelets.

The causes of ITP vary. Some cases are caused by drugs, and others are associated with infection, pregnancy, or immune disorders such as systemic lupus erythematosus. About half are classified as "idiopathic," meaning the cause is unknown.

The main symptom is bleeding, which can include bruising, or ecchymosis, and tiny red dots on the skin or mucous membranes, or petechiae. In some instances bleeding from the nose, gums, digestive or urinary tracts may also occur. In rare cases, there is also some bleeding in the brain.

The physician takes 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 is 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, megakaryocytes, in the marrow, and to rule out other diseases such as metastatic cancer; a cancer that has spread to the bone marrow; or leukemia. Another blood sample might be drawn to check for other conditions sometimes associated with thrombocytopenia such as lupus.

Acute, or temporary, thrombocytopenic purpura is the most common in young children. Both genders are equally affected. Symptoms often, but do not necessarily, follow those of a viral infection. About eighty-five percent of children recover within a year and the problem doesn't return.

Thrombocytopenic purpura is considered chronic when it has lasted more than six months. The onset of illness may be at any age. Adults more often have the chronic disorder. Females are affected two to three times more than males.

If the doctor thinks a drug is the cause of the thrombocytopenia, most often it will be discontinued. 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, however, drugs that alter the immune system's attack on the platelet are prescribed. These may include corticosteroids, such as prednisone, intravenous infusions of immune globulin. Another treatment usually results in an increased number of platelet is removal of the spleen, the organ that destroys antibody-coated platelets. Other drugs such as vincristine, azathioprine, danazol, cyclophosphamide, or 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.

Except in certain situations, for example; internal bleeding and preparation for surgery, platelet transfusions usually are not beneficial and, therefore, are seldom performed. Because all therapies can have risks, it is important that over treatment, that is, 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 like a helmet 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 made in consultation with the patient's hematologist.

Blood specialists, or hematologists, are experts in the diagnosis and treatment of these disorders. These doctors practice in most mid- and large-size cities. A majority of medical centers have hematology divisions in their medicine or pediatrics departments, and patients who need evaluation, treatment, or information can often be referred there.

Thanks to EMedicine and NIH for my information in writing this :0)


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