Idiopathic thrombocytopenic purpura (ITP) is a common bleeding disorder in childhood, characterized by spontaneous bleeding, thrombocytopenia, prolonged bleeding time, poor clot retraction, positive capillary fragility test, increased or normal megakaryocytes in the bone marrow, and impaired megakaryocyte maturation.

bubble_chart Etiology

The exact cause is not yet fully understood, but it is currently widely believed to be an autoimmune disease. Approximately 80% of patients have a history of infection prior to onset, particularly viral infections, which are more common. Using specialized testing methods, about 60% of patients have an anti-self-platelet antibody in their serum, and sometimes this occurs concurrently with autoimmune hemolytic anemia. If the plasma of a patient is transfused into a healthy individual, it can cause thrombocytopenia in the recipient, even leading to purpura. Conversely, if platelets from a healthy person are transfused into the patient, they are rapidly destroyed in the patient's body. In newborns with the disease, about half of the mothers have the same condition. Recent treatment with immunomodulatory drugs has shown relatively good efficacy for this disease.

The role of the spleen in the pathogenesis of this disease remains controversial. When splenic hyperfunction occurs, it can destroy platelets coated with antibodies. The spleen is also involved in antibody production, directly affecting megakaryocytes in the bone marrow and inhibiting platelet maturation. In some patients, splenectomy can alleviate symptoms, increase platelet counts, and stop bleeding.

Increased capillary wall permeability and reduced vascular tone are also related to the disease to some extent.

Children of any age can develop the disease, but it is most common in children aged 2 to 8, accounting for more than 70% of all pediatric cases.

Widespread spontaneous bleeding occurs in the skin and mucous membranes, often manifesting as petechiae or ecchymoses. Epistaxis, gum bleeding, hematemesis, hematochezia, and hematuria may also be observed. Adolescent girls may experience hypermenorrhea. Mild cases exhibit no special symptoms other than skin and mucous membrane bleeding, while severe cases may be accompanied by fever, pallor, circulatory failure, and occasionally hemorrhagic shock. Intracranial hemorrhage is rare but may present with symptoms of increased intracranial pressure, such as headache, vomiting, drowsiness or restlessness, unconsciousness, and spasms. Newborns of mothers with this disease may also develop symptoms, but most recover spontaneously within 1 to 2 weeks.

The disease can be divided into acute and chronic types:

Acute type: More common in infants and young children, often occurring in spring. Symptoms appear suddenly with severe bleeding, and infections frequently precede or coincide with onset. Some patients may progress to the chronic type.

bubble_chart Auxiliary Examination

The platelet count is generally below 60×10⁹/L (60,000/mm³), with a bleeding time exceeding 3 minutes, sometimes lasting up to an hour or longer; poor or absent clot retraction; positive capillary fragility test; anemia may occur if bleeding is excessive or recurrent; when platelets are severely reduced, clotting time may be prolonged due to a lack of platelet thrombin.

Bone marrow findings: In cases of severe bleeding, a hyperplastic bone marrow picture may appear. In the acute type, the number of megakaryocytes is normal or slightly increased, with a predominance of immature megakaryocytes if elevated; in the chronic type, megakaryocytes are increased, mostly granular megakaryocytes.

bubble_chart Treatment Measures

1. General Treatment: Rest quietly, avoid trauma, actively control infections, administer vitamin C and P. For secondary anemia, iron supplements should be given.
2. Hemostatic injections or oral etamsylate may be used. For epistaxis, adrenaline-soaked cotton balls can be applied for packing.
3. Immunosuppressive Therapy: For acute and severe bleeding cases, hydrocortisone 5–10 mg/kg per day should be administered intravenously in two divided doses. After symptoms improve, switch to oral prednisone. Alternatively, oral prednisone 2 mg/kg per day (severe cases may increase to 4 mg/kg per day) can be started initially. For acute cases, gradually reduce the dose and discontinue after bleeding stops. If the medication is used for less than a week, discontinuation does not require tapering. For chronic cases, if medication is used for more than a week, gradually reduce the dose and maintain the minimum effective dose to keep platelets within the normal range for 3–6 months before discontinuation. Azathioprine (1–1.5 mg/kg per day) or cyclophosphamide (1.5 mg/kg per day) may also be used. Combining both drugs yields better results.
4. Transfusion of Fresh Blood or Platelets: For bleeding accompanied by anemia, fresh blood transfusion can improve anemia. To save the patient and rapidly control bleeding, concentrated platelet transfusion may be administered if conditions permit.
5. Anemia: In addition to blood transfusion, iron supplements or other adjunctive medications such as coenzyme A, folic acid, leucogen, ampeptide element, nucleotides, and ATP may be given.
6. Chinese Medicinals: For cases of dual deficiency of qi and blood with blood failing to circulate properly, modified Returning to Spleen Decoction may be used.
7. Surgical Therapy: For recurrent severe bleeding unresponsive to long-term treatment with the above methods, splenectomy may be considered.

bubble_chart Differentiation

1. Secondary thrombocytopenic purpura
   1. Acute and chronic infectious diseases such as measles, hepatitis, sepsis, epidemic cerebrospinal meningitis, miliary subcutaneous nodules, and infections complicated by DIC can all lead to secondary thrombocytopenia.
   2. Chemical and physical factors such as drugs, heavy metal poisoning, burns, and radiation can also cause thrombocytopenia. Relevant medical history, clinical manifestations, and the absence of increased megakaryocytes in the bone marrow without maturation disorders can aid in differentiation.
   3. Acute leukemia presents with both bleeding and pancytopenia, generally poor condition, severe anemia, often accompanied by varying degrees of hepatosplenomegaly. Leukemic cells can be detected in peripheral blood, and bone marrow examination can confirm the diagnosis when necessary.
   4. Aplastic anemia: In addition to bleeding and thrombocytopenia, pancytopenia is present, along with hypoplastic bone marrow.
2. Thrombasthenia: Although the clinical manifestations are similar, there is no thrombocytopenia, and platelet counts are mostly above 300–500×10⁹/L, which aids in differentiation.
3. Allergic purpura: Purpura is commonly seen on the skin of the limbs and buttocks as hemorrhagic papules, symmetrically distributed, more on the extensor surfaces than the flexor surfaces. Urticaria and angioneurotic edema may be observed. Platelet counts are not reduced, and bleeding time and clot retraction time may be normal, making differentiation generally straightforward.