Idiopathic thrombocytopenic purpura, also known as primary or immune thrombocytopenic purpura, is a group of bleeding disorders caused by immune-mediated excessive platelet destruction. ITP is the most common form of thrombocytopenic purpura. The incidence is about 5-10/100,000 population, and there is a tendency to increase the incidence in elderly people over 65 years old. It can be clinically divided into acute and chronic forms, with the former occurring in children and the latter in adults. The incidence is similar in men and women, with a higher incidence in women of childbearing age than in men of the same age group. The etiology of this disease is unknown. The acute form occurs after the acute viral upper respiratory tract infection has healed, suggesting that thrombocytopenia is related to the immune response to the primary infection. Anti-platelet antibodies in the serum can be detected in about half of the patients with chronic type. Clinical manifestations: Acute ITP occurs in more than half of the children, usually with rapid onset, most patients have a history of upper respiratory tract infection 1-2 weeks before the onset, especially a history of viral infection, clinical manifestations are generalized skin and mucous membrane bleeding, serious cases may have blood blisters and hematoma formation. Nasal bleeding, gum bleeding, oral mucosa and tongue bleeding are common, and injuries and injection sites may ooze blood or form petechiae of varying sizes. When platelets are below 20×109/L, visceral appearances such as vomiting blood, black stool, hemoptysis, blood in urine, vaginal bleeding, etc. Intracranial appearances can cause severe headache, impaired consciousness, paralysis and convulsions, which are the main cause of death in this disease. Excessive bleeding can lead to varying degrees of anemia, decreased blood pressure and even hemorrhagic shock. The chronic form of ITP occurs in young women and is usually insidious in onset, often manifesting with varying degrees of skin and mucosal bleeding, mostly mild and limited. The patient’s condition may be suddenly aggravated by infection, with extensive and severe bleeding from the skin, mucous membranes and internal organs. In those with a disease duration of more than six months, some may bleed with mild splenomegaly. Third, the examination. 1. Platelets (1) decreased platelet count; (2) increased mean platelet volume; (3) prolonged bleeding time; (4) poor clot contraction. Platelet function is generally normal. Bone marrow picture (1) Acute type of bone marrow megakaryocyte count is normal or increased, while chronic type of megakaryocytes are usually significantly increased; (2) impaired maturation of megakaryocytes, especially in acute type, manifested by smaller size of megakaryocytes, reduced intracytoplasmic granules, and increased infantile megakaryocytes; (3) significant reduction of megakaryocytes with platelet formation; (4) normal red lineage and granulocytic and monocytic lineage. (3) Platelet survival time is significantly shorter in more than 90% of patients. (4) Others may have varying degrees of normocytic or microcytic hypochromic anemia, and a few may find evidence of autoimmune hemolysis. The diagnostic criteria for ITP in China are: 1. multiple laboratory tests for platelet count <100×109/L; 2. no enlargement of the spleen or only mild enlargement; 3. increased or normal number of megakaryocytes in bone marrow examination with maturation disorders; 4. one of the following five items should be present: effective prednisone treatment; effective splenectomy treatment; increased PAIgG; increased PAC3; shortened platelet life span Shortening; 5. Exclude secondary thrombocytopenia; 6. ITP heavy criteria: more than 3 bleeding sites; platelet count <10×109/L. V. Treatment. 1, general treatment: those with severe bleeding should pay attention to rest. Those with platelets below 20×109/L should be strictly bedridden to avoid trauma. 2.Glucocorticoid: Generally, it is the first choice of treatment, and the recent efficiency is 80%. Prednisone 1mg/(kg? d) is commonly used, divided or taken at once. In severe cases, dexamethasone or methylprednisolone is used in equal doses intravenously, and then taken orally after improvement. If the platelets rise to normal or close to normal, gradually reduce the dose (5mg per week), and finally maintain the treatment with 5-10mg/d for 3-6 months. ITP patients with no obvious bleeding tendency and platelet count >30×109/L can be left untreated. 3.Splenectomy: For those who are ineffective in glucocorticoid treatment, glucocorticoid maintenance amount is more than 30mg/d and have contraindication to glucocorticoid, splenectomy can be performed, the treatment efficiency is about 70-90%, and the need for glucocorticoid can be reduced for those who are ineffective. 4. Immunosuppressants: should not be used as the first choice. It is suitable for those who have poor efficacy of glucocorticoids or splenectomy, those who have contraindications to glucocorticoids or splenectomy, and those who combine with glucocorticoids to improve the efficacy and reduce the dosage of glucocorticoids. The main drugs are vincristine, cyclophosphamide, azathioprine, cyclosporine, mycophenolate, rituxan monoclonal antibody, etc. 5.Other: Danazol, amineptin, etc. 6.Management of emergencies: for those with platelets below 20×109/L; those with severe and extensive bleeding; those suspected of having or having had intracranial hemorrhage; those who will recently perform surgery after delivery. Platelet transfusion, intravenous infusion of high-dose immunoglobulin, high-dose hormone shock therapy and plasma exchange can be given if necessary. Prognosis Acute ITP is mostly self-healing, with a shorter course and a better prognosis. Chronic ITP is often recurrent, the duration of the disease varies, the general prognosis is still good. In severe thrombocytopenia, death can occur due to intracranial hemorrhage or bleeding of important organs. Seven, prevention of cold, close observation of the changes of purple spots. Such as density, color, size, etc., pay attention to body temperature, mental and bleeding conditions, which can help to understand the prognosis and regression of the disease, so as to be dealt with in a timely manner. Avoid traumatic injury, and those with serious bleeding must be absolutely resting in bed. For chronic patients, it is important to take part in exercise, keep a happy mood, eat a soft diet, and if there is bleeding in the gastrointestinal tract, eat a semi-liquid or liquid diet, and refrain from eating tobacco, alcohol, spicy and stimulating things. If the rash is itchy, use furnace glycolic lotion or Jiuhua powder lotion to apply, pay attention to skin hygiene, avoid scratching and cutting the skin to cause infection.