thrombocytopenic purpura

a hemorrhagic disease characterized by extravasation of blood into the tissues, under the skin, and through the mucous membranes, and producing spontaneous bruises, ecchymoses, and petechiae (small hemorrhagic spots) on the skin. (See plate in Dermatology Atlas.) When accompanied by a decrease in the circulating platelets, it is called thrombocytopenic purpura; when there is no decrease in the platelet count, it is called nonthrombocytopenic purpura. adj., adj purpu´ric.

There are two general types of thrombocytopenic purpura: primary or idiopathic, in which the cause is unknown, and secondary or symptomatic, which may be associated with exposure to drugs or other chemical agents, systemic diseases such as multiple myeloma and leukemia, diseases affecting the bone marrow or spleen, and infectious diseases such as rubella (German measles).

Any rash in which blood cells leak into the skin or mucous membranes, usually at multiple sites. Purpuric rashes often are associated with disorders of coagulation or thrombosis. Pinpoint purpuric lesions are called petechiae; larger hemorrhages into the skin are called ecchymoses. Synonym: peliosis See: illustration

Any of a group of purpuras caused by a variety of agents, including bacteria, drugs, and food. The immune complexes associated with type III hypersensitivity reaction damage the walls of small blood vessels, leading to bleeding. Synonym: nonthrombocytopenic purpura

Purpura resulting from excess fibrinolytic activity of the blood.

A rapidly progressing form of purpura occurring principally in children. It is of short duration and frequently fatal.

A hemorrhagic autoimmune disease in which there is destruction of circulating platelets, caused by antiplatelet autoantibodies that bind with antigens on the platelet membrane, making platelets more susceptible to phagocytosis and destruction in the spleen. It occurs as an acute disease in children, usually between ages 2 and 6, and often follows a viral infection. Chronic ITP seldom follows an infection and is commonly linked to immunologic disorders such as lupus erythematosis or patients with acquired immunodeficiency syndrome who are exposed to the rubella virus. It also is linked to drug reactions, and occurs in cases of alcohol, heroin, or morphine abuse. It mainly affects adults younger than age 50, especially women between 20 and 40. Opsonization of platelets by autoantibodies stimulates their lysis by macrophages, esp. in the spleen. Synonym: Henoch-Schönlein disease; hemorrhagic purpura; thrombocytopenic purpura; thrombopenic purpuraillustration;

CAUTION!

People with ITP should take special precautions to avoid injuries in contact sports. Aspirin and other drugs that may cause bleeding should only be taken by people with ITP under direction of an experienced physician.

Symptoms

Symptoms may include bleeding from the nose, the gums, or the gastrointestinal tract. Physical findings include petechiae, esp. on the lower extremities, and ecchymoses. Laboratory findings: The platelet count is usually less than 20,000/mm³, bleeding time is prolonged, and may be associated with mild anemia as a result of bleeding.

Treatment

If patients are asymptomatic (i.e., have no active bleeding) and have platelet counts of about 50,000/mm³, treatment is not needed (4 out of 5 patients recover without treatment). Treatment for symptomatic patients, or patients with very low platelet counts, usually is with glucocorticoids or immune globulin for acute cases and corticosteroids for chronic cases. For those who do not respond within 1 to 4 months, treatment may include high-dose corticosteroids, intravenous immune globulin (IVIG), immunosupression, immunoabsorption apheresis using staphylococcal protein-A columns to filter antibodies out of the bloodstream, AntiRhD therapy for those with specific blood types, splenectomy, or chemotherapeutic drugs such as vincristine or cyclophosphamide.

Patient care

Platelet count is monitored closely. The patient is observed for bleeding (petechiae, ecchymoses, epistaxis, oral mucous membrane or GI bleeding, hematuria, menorrhagia) and stools, urine, and vomitus are tested for occult blood. The amount of bleeding or size of ecchymoses is measured at least every 24 hr. Any complications of ITP are monitored. The patient is educated about the disorder, prescribed treatments, and importance of reporting bleeding (such as epistaxis, gingival, urinary tract, or uterine or rectal bleeding) and signs of internal bleeding (such as tarry stools or coffee-ground vomitus). The patient should avoid straining during defecation or coughing because both can lead to increased intracranial pressure, possibly causing cerebral hemorrhage. Stool softeners are provided as necessary to prevent tearing of the rectal mucosa and bleeding due to passage of constipated or hard stools. The purpose, procedure, and expected sensations of each diagnostic test are explained. The role of platelets and the way in which the results of platelet counts can help to identify symptoms of abnormal bleeding are also explained. The lower the platelet count falls, the more precautions the patient will need to take; in severe thrombocytopenia, even minor bumps or scrapes can result in bleeding. The nurse guards against bleeding by taking the following precautions to protect the patient from trauma: keeping the side rails of the bed raised and padded, promoting use of a soft toothbrush or sponge-stick (toothette) and an electric razor, and avoiding invasive procedures if possible. When venipuncture is unavoidable, pressure is exerted on the puncture site for at least 20 min or until the bleeding stops. During active bleeding, the patient maintains strict bedrest, with the head of the bed elevated to prevent gravity-related intracranial pressure increases, possibly leading to intracranial bleeding. All areas of petechiae and ecchymoses are protected from further injury. Rest periods are provided between activities if the patient tires easily. Both patient and family are encouraged to discuss their concerns about the disease and its treatment, and emotional support is provided and questions answered honestly. The nurse reassures the patient that areas of petechiae and ecchymoses will heal as the disease resolves. The patient should avoid taking aspirin in any form as well as any other drugs that impair coagulation, including nonsteroidal anti-inflammatory drugs. If the patient experiences frequent nosebleeds, the patient should use a humidifier at night and should moisten the nostrils twice a day with saline. The nurse teaches the patient to monitor the condition by examining the skin for petechiae and ecchymoses and demonstrates the correct method to test stools for occult blood. If the patient is receiving corticosteroid therapy, fluid and electrolyte balance is monitored and the patient is assessed for signs of infection, pathological fractures, and mood changes. If the patient is receiving blood or blood components, they are administered according to protocol; vital signs are monitored before, during, and after the transfusion, and the patient is observed closely for adverse reactions. If the patient is receiving immunosuppressants, the patient is monitored closely for signs of bone marrow depression, opportunistic infections, mucositis, GI tract ulceration, and severe diarrhea or vomiting. If the patient is scheduled for a splenectomy, the nurse determines the patient's understanding of the procedure, corrects misinformation, administers prescribed blood transfusions, explains postoperative care and expected activities and sensations, ensures that a signed informed consent has been obtained, and prepares the patient physically (according to institutional or surgeon's protocol) and emotionally for the surgery. Postoperatively, all general patient care concerns apply. Normally, platelets increase spontaneously after splenectomy, but the patient may need initial postoperative support with blood and component replacement and platelet concentrate. The patient with chronic ITP should wear or carry a medical identification device.

An obsolete term for Henoch-Schönlein purpura.

An abnormal immune-mediated fall in the number of circulating platelets, caused by a recipient's reaction to foreign antigens on platelets received during a transfusion. Although the immune reaction normally starts against the donated platelets, in PTP host (recipient) platelets are also attacked, leading to a severe decrease in platelet numbers about a week, plus or minus 2 days, after the platelet transfusion. The consequences of a low platelet count may include bleeding, bruising, or discoloration of the skin.

Purpura with joint pain, colic, bloody stools, and vomiting of blood.

Purpura occurring in debilitated and aged people with ecchymoses and petechiae on the legs.

Purpura that is not associated with systemic illness.

A rare, life-threatening disease marked by widespread aggregation of platelets throughout the body, neurological dysfunction, and renal insufficiency. The disease is triggered by a deficiency of an enzyme that cleaves von Willebrand factor (a blood clotting protein). This deficiency results in blood clots in small blood vessels throughout the body. Shifting neurological signs such as aphasia, blindness, and convulsions are often present. See: hemolytic uremic syndrome

Etiology

The disease has occurred in patients taking certain drugs (e.g., ticlopidine); in some patients with cancer or HIV-1 infection; and in some pregnant women.

Treatment

Plasmapheresis or infusions of fresh frozen plasma are effective in treating the disease.

A blister filled with blood; colloquially, a blood blister.