Primary immune thrombocytopenia (ITP) is a disease characterized by the production of autoantibodies against platelets in the body, leading to the phagocytosis and destruction of platelets in the liver and spleen, resulting in a significant decrease in platelet count and clinical manifestations of bleeding.

bubble_chart Diagnosis

1. Medical History and Symptoms

(1) History Inquiry: Note: ① Severity, triggers, and sites of bleeding; age of onset. ② History of viral infection within 1 month before onset. ③ History of medication use or exposure to harmful substances. ④ Presence of autoimmune diseases, tumors, or malignant hematologic diseases.

(2) Clinical Symptoms: Dizziness, fatigue, epistaxis or gum bleeding, hypermenorrhea in adult women. Severe cases may present with hematemesis or hematochezia. Very few patients (<1%）可發生顱內出血：出現顱內高壓表現，甚至昏迷。

2. Physical Examination Findings

Petechiae and ecchymoses may be observed on the skin and mucous membranes; severe cases may exhibit large ecchymoses or hematomas. Blood blisters may appear on oral mucous membranes, with gum bleeding. The liver and spleen are either not enlarged or show grade I enlargement. Neurological signs may be present in cases of intracranial hemorrhage.

3. Auxiliary Examinations

1. Blood Test: Generally no anemia (grade I anemia may occur in severe bleeding cases), normal white blood cell count. Platelet count is reduced.

2. Coagulation Tests: Prolonged bleeding time; normal clotting time, prothrombin time, and thrombin time.

3. Bone Marrow Examination: Normal hyperplasia, increased megakaryocyte count with maturation disorder (in most patients, platelet-producing megakaryocytes <30%）。

4. Autoantibody Tests: Significant increase in platelet-associated antibodies (PAIgG); increased platelet-associated C3 (PA C3).

4. Differential Diagnosis:

Conditions to exclude include acute leukemia, lymphoma, thrombotic thrombocytopenic purpura, autoimmune diseases, Evans syndrome, and drug-induced thrombocytopenia.

bubble_chart Treatment Measures

1. Glucocorticoids: Prednisone: 1–2 mg/kg, once or divided into 3 doses per day, orally; after platelets normalize and stabilize, gradually reduce to a maintenance dose, with a treatment course of 3–6 months. Methylprednisolone: 500 mg/m², intravenous drip, for 3–5 days, then switch to prednisone.

2. Immunoglobulin: For patients with platelet counts <20×10⁹/L, accompanied by life-threatening bleeding or requiring major surgery, use immunoglobulin: 0.4 g/kg·d for 5 consecutive days.

3. Immunosuppressants: Vincristine: 1 mg via continuous intravenous drip over 8–12 hours, once per week for 3–6 doses. Etoposide: 60–100 mg, administered similarly. High-dose cyclophosphamide may also be used.

4. Splenectomy: Indications: patients with contraindications to hormone therapy; those unresponsive to hormone treatment; or those requiring high-dose hormone maintenance therapy.

5. Platelet transfusion: For patients with life-threatening bleeding or requiring major surgery (4–6 units per dose).

6. Others: Danazol: 200 mg, 3 times daily, orally, with a treatment course >6 months. Interferon: 3 million units, subcutaneously, 3 times per week, with a treatment course of 3–6 months.