What Are the Causes of Thrombocytopenia in Children?

Thrombocytopenic purpura is a hemorrhagic disease characterized by thrombocytopenia, which is mainly manifested by the bleeding tendency of the skin and organs and a significant reduction in platelets. It can be divided into idiopathic thrombocytopenic purpura and secondary thrombocytopenia Purpura and thrombotic thrombocytopenic purpura.

Basic Information

English name

thrombocytopenia purpura

Visiting department

Hematology

Common causes

Excessive platelet destruction, impaired or ineffective platelet production, etc.

Common symptoms

Skin purpura, petechiae, petechiae, oral and nasal bleeding

Causes of thrombocytopenic purpura

Idiopathic thrombocytopenic purpura

Adult idiopathic thrombocytopenic purpura is currently considered to be an organ-specific autoimmune hemorrhagic disease. It is caused by the production of anti-platelet autoantibodies in the human body, which leads to the destruction of the mononuclear macrophage system by excessive platelets, leading to thrombocytopenia. The reason is unclear. Idiopathic thrombocytopenic purpura in children usually has a history of viral infection.

2. Secondary thrombocytopenic purpura

(1) Impaired or ineffective platelet production 1) Reduced megakaryocyte production Physical and chemical factors. Bone marrow infiltrative disease. hematopoietic stem cell disease. Infectious diseases. Disorders of platelet production and regulation. hereditary diseases. 2) Ineffective platelet production See vitamin B ₁₂ , folic acid deficiency, partial paroxysmal nocturnal hemoglobinuria, and myelodysplastic syndromes.

(2) Increased platelet destruction or excessive consumption 1) Immune destruction Drug-related antibodies. Some diseases with abnormal immune response. infection-related thrombocytopenia. Immune thrombocytopenia. 2) Non-immune destruction Vasculitis, arterial intubation, extracorporeal circulation, etc. 3) Excessive platelet consumption is mainly seen in thrombotic microangiopathy.

(3) abnormal platelet distribution Splenomegaly caused by various reasons.

3. Thrombotic thrombocytopenic purpura

The damage of microvascular endothelial cells by various causes reduces the antithrombotic ability of endothelial cells.

Clinical manifestations of thrombocytopenic purpura

Idiopathic thrombocytopenic purpura

It is clinically divided into two types: acute and chronic.

(1) Acute type is common in children. Onset is rapid, with a few cases showing fulminant onset. May have mild fever, chills, sudden and extensive skin mucosal purpura, and even large bruises. The skin petechiae are mostly systemic, and the lower limbs are more common and distributed evenly. Mucosal hemorrhage is more common in the nasal cavity, gums, and blood blisters in the mouth.

(2) Chronic type It is common in young women, the onset is hidden, and the symptoms are mild. Bleeding often recurs, and each bleeding can last from days to months. Skin purpura, petechiae, petechiae are more common in the lower extremities or below the tourniquet. There may be bleeding from the nasal cavity, gums, and oral mucosa. Female menstruation is sometimes the only symptom.

2. Secondary thrombocytopenic purpura

The patient has a history of primary disease or a history of exposure to certain causative factors before the onset of mild or moderate thrombocytopenia without bleeding. Severe thrombocytopenia often has skin, mucosal petechiae, purpura, petechiae, nosebleeds, oral blood Blister etc. In severe cases, intracranial hemorrhage occurs, which is the main cause of death.

3. Thrombotic thrombocytopenic purpura

(1) Decreased depletion of platelets causes extensive bleeding in the skin, mucous membranes and internal organs, and severe cases have intracranial hemorrhage.

(2) Red blood cell damage Microvascular disease hemolysis caused by mechanical damage of red blood cells, with varying degrees of anemia, jaundice, or splenomegaly.

(3) Neuropsychiatric symptoms Neuropsychiatric symptoms are characterized by uncertainties. Patients have varying degrees of disturbance of consciousness, dizziness, headache, convulsions, slurred speech, impaired consciousness, mental disorders, lethargy and even coma. Cerebral nerve palsy, paresis, or hemiplegia may occur in some cases, but it usually recovers within hours.

(4) Extensive involvement of renal blood vessels When extensive renal blood vessels are involved, proteinuria, microscopic hematuria, and cast urine appear. In severe cases, azotemia and acute renal failure can occur.

(5) Fever can be seen in different periods.

(6) Microvascular involvement of internal organs in the heart, lung, and abdominal cavity can cause corresponding symptoms.

Thrombocytopenic purpura test

Blood routine

Blood routine shows only thrombocytopenia and other blood cells in the normal range. Some patients have iron deficiency due to blood loss, which may be accompanied by anemia. Reticulocyte counts were normal in ITP alone. Thrombotic thrombocytopenic purpura usually has a marked decrease in platelets, moderate to severe anemia, and elevated reticulocytes.

2. Peripheral blood smear

The presence of broken red blood cells should exclude thrombotic thrombocytopenic purpura and hemolytic uremic syndrome. The appearance of giant platelets requires consideration of hereditary platelet dysfunction.

3. Bone marrow smear

In patients with idiopathic thrombocytopenic purpura, bone marrow hyperplasia is active, and megakaryocytes are normal or increased. The more prominent change is the imbalance of megaplasmic nuclear plasma maturation, fewer particles in the cytoplasm, and significant reduction or lack of platelet megakaryocytes.

4. Antiplatelet autoantibody detection

Most adults with idiopathic thrombocytopenic purpura (ITP) have elevated platelet-associated immunoglobulin G (PAIgG) and / or platelet-associated immunoglobulin M (PAIgM), and sometimes immunoglobulin A (IgA).

5. Primary disease related examination

Examination of the incidence of secondary thrombocytopenic purpura.

6. Hemolysis-related examination

According to the degree of hemolysis, thrombotic thrombocytopenic purpura may reduce plasma globin levels, increase indirect bilirubin, hemoglobinuria, etc., but anti-human globulin test (Coombs test) is negative.

Thrombocytopenic purpura diagnosis

Make a corresponding diagnosis based on medical history, clinical manifestations and related examinations.

Thrombocytopenic Purpura Treatment

Idiopathic thrombocytopenic purpura

Treatment should be individualized. Generally speaking, the platelet count is greater than 30 × 10 ⁹ / L, and those who have no tendency to bleeding can be observed and regularly checked; the platelet count is between (20 30) × 10 ⁹ / L, depending on the patient's clinical manifestation / degree of bleeding And risk; platelets less than 20 × 10 ⁹ / L should usually be treated. Patients with severe bleeding tendency should stay in bed to avoid trauma and avoid taking drugs that affect platelet function. The purpose of the treatment of this disease is to control the bleeding symptoms and reduce the destruction of platelets, but it is not emphasized to increase the platelet count to normal to ensure that patients are not at risk due to bleeding and do not cause serious adverse reactions due to overtreatment.

(1) Initial treatment Glucocorticoid. Severe patients can use large doses of gamma globulin.

(2) Second-line therapy Alternative second-line treatment drugs include azathioprine, cyclosporine A, danazol, vinca alkaloids, morphomycolipid, CD20 monoclonal antibody, and so on. splenectomy. Anti-Rh (D) immunoglobulin can be used abroad. Thrombopoietin, thrombopoietin receptor agonist, etc.

2. Secondary thrombocytopenic purpura

Mainly for primary disease. Glucocorticoids can improve symptoms in severe bleeding and transfusion of platelet suspension if necessary. For immune thrombocytopenia, the application of glucocorticoids is mostly effective, and some patients can be treated with plasma exchange. Drug-induced thrombocytopenia should be discontinued immediately, and bleeding can improve on its own. Infectious thrombocytopenia should be actively treated with anti-infection. Generally, platelets can return to normal 2 to 6 weeks after infection control, and those with infection causing bone marrow suppression have a longer disease course. For hypersplenism, splenectomy is feasible. Cavernous hemangioma can be treated by irradiation or surgical resection.

3. Thrombotic thrombocytopenic purpura

Plasma exchange is the primary treatment of choice.