Idiopathic Thrombocytopenia P... Health Article

Diagnosis

ITP is usually considered a diagnosis of exclusion, which means that the doctor makes a diagnosis by ruling out other possible causes for the symptoms and physical findings. The presence of fever, for example, does not indicate ITP, whereas fever may occur in lupus and some other types of thrombocytopenia. Likewise, the doctor will look for an enlarged spleen by pressing on (palpating) the abdomen; if the spleen is noticeably enlarged, ITP is not absolutely ruled out but is a less likely diagnosis. If ITP is suspected, the doctor will examine the child's skin for bruises, purpuric areas, or petechiae. If nosebleeds or bleeding from the mouth or other parts of the body have been reported, the doctor will examine these areas for other possible causes of bleeding. Individuals with ITP usually look and feel healthy except for the bleeding. If the child has had a recent childhood illness (measles, chickenpox) or a virus, the risk for ITP is greater, and this fact will be considered along with diagnostic testing results.

Diagnostic tests will begin with a complete blood count (CBC), including a platelet count. A blood test for autoantibodies may be performed early in the diagnostic process as well as a test for antiplatelet antibodies. Specific diagnostic tests for autoimmune diseases and viruses (CMV, EBV, and rheumatoid factor or RF) may be performed. Coagulation tests, including clotting time, will be performed to determine the ability of the child's blood to form a clot. Platelet aggregation tests may be performed to evaluate platelet function, particularly if the platelet count is low.

Children with ITP will usually have platelet counts below 20,000/mm³ and a prolonged clotting time. The size and appearance of the platelets may be abnormal, which is observed microscopically. The red blood cell count (RBC) and white blood cell count (WBC) are usually normal, although about 10 percent of individuals with ITP are also anemic (have reduced RBCs and hemoglobin). The bone marrow test yields normal results. Detection of antiplatelet antibodies in the blood usually confirms a diagnosis of ITP.

Treatment

There is no specific treatment for ITP except to manage symptoms. In most cases, the disorder will resolve within two to six weeks without medications or surgery. Nosebleeds can be treated with ice packs when necessary. General care may include asking parents to watch for bruising, petechiae, or other signs of recurrence. Parents are also advised to avoid giving the child aspirin, ibuprofen, or other over-the-counter pain medications because these drugs are known to lengthen the clotting time of blood.

Children with acute ITP who are losing large amounts of blood or bleeding into their central nervous system require emergency treatment. This may include transfusions of platelets, intravenous immunoglobulins, or prednisone. Prednisone is a steroid medication that decreases the effects of antibodies on platelets and eventually lowers antibody production. If the child has been treated before for ITP and has not responded to prednisone or immunoglobulins, surgery may be required to remove the spleen (splenectomy), an organ that sometimes stores platelets and keeps them out of the general blood circulation. Splenectomy is usually avoided in children younger than five years because of the increased risk of a severe postoperative infection. In older children, however, splenectomy is recommended if the child has been treated for 12 months without improvement, if the ITP is very severe or is getting worse, or if the child begins to bleed into the head or brain.

Children with chronic ITP can be treated with prednisone, immune globulin, or large doses of intravenous gamma globulin. Although 90 percent of those with ITP respond to immunoglobulin treatment, it is an expensive treatment. Response to prednisone therapy is about 80 percent. Platelet transfusions are not recommended for routine treatment of ITP. If platelet levels do not improve within one to four months, or high doses of prednisone are required, splenectomy may be recommended. If the patient is an adolescent female with extremely heavy periods, splenectomy may also be recommended. Adults treated with splenectomy usually experience remission of chronic ITP. All medications for ITP are given either orally or intravenously; intramuscular injection is avoided because of the possibility of causing bleeding into the skin.