3. IDIOPATHIC (PRIMARY) THROMBOCYTOPENIC PURPURA GENERAL CONSIDERATION
     Thrombocytopenia is the result of increased platelet destruction; the platelet count is closely related to the rate of destruction. Normal platelet survival is 8 to 10 days. But the survival is usually only 1 to 3 days in chronic idiopathic thrombocytopenic purpura and even less in the acute form. Most patients have increased levels of IgG on their platelets. Despite an apparent increase in number of megakaryocytes in the marrows, platelet production is usually not increased; antibodies may disturb megakaryocytic development and lead to ineffective production. The disorder may be postinfectious, e.g. following infectious mononucleosis or rubella; may be caused by isoimmunity; e.g. following transfusions or in the neonatal period; may develop into diseases with autoimmune manifestations; e.g. lupus erythematosus or lymphoproli- ferative disorders; or may follow the use of certain drugs, e.g. quinidine, quinine, thiazides, sulfonamides, phenylbutazone, acetazolamide, aminosalicylic acid, gold, heparin and others.
     The spleen while not large, contributes to the thrombocytopenia in 2 ways: (1)
it sequesters the subtly damaged platelets and (2) it manufactures some antibody.
     Acute thrombocytopenic purpura is more common in children; 85% of patients
are less than 8 years old. It usually remits spontaneously in 2 weeks to a few months.
Chronic thrombocytopenic purpura may start at any age and is more common in females. At onset it cannot be distinguished from the acute form by laboratory test. There may be clinical remissions and exacerbation, but the platelet count is always low.
CLINICAL MANIFESTATIONS
     The onset may be sudden with petechiae, epistaxis, bleeding gums, vaginal
bleeding, gastrointestinal bleeding or hematuria. In the chronic form, there may be a history of easy bruising and recurrent showers of petechiae, particularly in pressure areas. The spleen is not palpable.
     Laboratory findings. The platelet count is below 100,000/ul and may be below
10,000/ul. Platelets may be absent on the peripheral blood smear. White cells are not affected. Anemia, if present, is secondary to blood loss.
     The bone marrow megakaryocytes are increased in number but not surrounded
by platelets; they are abnormal, with single nuclei, scant cytoplasm, and often
vascuoles. The chief value of the marrow examination is to rule out leukemia and
aplastic anemia.
     The bleeding time is prolonged but PTT and PT are normal. Clot retraction is
poor. Prothrombin consumption is decreased in severe cases. Capillary fragility
(Rumpelleeds test) is greatly increased. An antinuclear antibody (ANA) test and a
prothrombin time and PTT should be done to look for lupus erythematosus, which
may present as purpura.
DIAGNOSIS
     Essentials of diagnosis in Western medicine.
     ? Petechiae, ecchymoses, epistaxis, easy bruising.
     ? No splenomegaly.
     ? Decreased platelet count, prolonged bleeding time, poor clot retraction.
     In traditional Chinese medicine, the condition is termed "yin purpura" or "blood symptom complex."
TREATMENT
I. Treatment in Western medicine.
     1. General measures
     Patients should avoid trauma, sports, elective surgery and tooth extraction. All unnecessary medications and exposure to potential toxins must be discontinued.
     Children with mild purpura following viral infections do not require any therapy. They should be observed until petechiae disappear and the platelet count returns to normal.
     2. Corticosteriods
     Corticosteroids are warranted in patients with moderately severe purpura of
short duration, especially when there is bleeding from the gastrointestinal or genitourinary tract. Corticosteroids are also given to patients with purpura who have complications contraindicating surgery. Prednisolone 10 to 20mg 4 times daily, is usually required to control bleeding. The dosage is continued until the platelet count returns to normal, and then it is gradually decreased.
     3. Splenectomy
     Splenectomy is indicated for all patients with well-documented thrombocytopenic purpura of more than 1 year's duration, for all patients with moderately severe purpura who have relapsed 2 to 3 times after corticosteroid therapy and for all patients with severe idiopathic thrombocytopenic purpura who do not respond to corticosteroids.
     4. Immunosuppressive therapy
     In patients who do not respond to corticosteroids and in whom splenectomy has failed to raise the platelet count, either vincristine, 1.4mg/m2, or vinblastine, 7.5mg/m2, once weekly intravenously for 4 to 6 weeks, may raise the platelet count to acceptable levels without further maintenance therapy.
II. Treatment in traditional Chinese medicine.
     Herb therapy
     A. For purpura due to deficiency of Qi and stagnant blood.
     The skin of the patient with petechiae and ecchymoses is easy to bruise, particularly in the pressure areas. Usually, the patients may feel short of breath with low and weak voice, and pale complexion. The tongue is swollen and delicate and the pulse is weak and rapid. The rule of treatment is to tonify Qi and activate blood. The most effective formula is Huo Luo Xiao Lin Dan Jia Jian.
     The constituents are:
     Chinese angelica 20g
     Root of red rooted salvia 30g
     Olibanum  6g
     Common myrrh tree 6g
     Unpeeled root of herbaceus peony 30g
     Root-bark of peony 30g
     Milk veteh 60g
      Asian puccoon  30g
      Madder 15g
      Node of lotus rhizome  15g
      Donkey-hide gelatin (melted) 10g
      Licorice root  6g
      Root of pseudo-ginseng  3g
      Decoction and dosage. All the above herbs are put together into a boiler to be simmered twice and then the broth of each mixed, half of the mixed broth each time, twice a day. Two to four doses are prescribed.
      B. For purpura due to failure of the spleen to regulate the blood.
      The skin of the patient with petechiae ecchymoses is easy to bruise, but usually is accompanied with gastrointestinal bleeding or hematuria, vaginal bleed