I. Physical immune thrombocytopenia
There is an incubation period before the onset of hemorrhagic symptoms, which can occur within a few hours after taking the drug in short cases, or months later in long cases. Generally 5-10 days. Often accompanied by chills, fever, headache, nausea, vomiting, etc.
Other immune thrombocytopenia
Patients show generalized skin purpura, epistaxis or excessive menstruation in women, fatigue and weakness, pallor, and deepened urine color. Occasionally, signs of kidney damage such as hypertension, hematuria, azotemia, etc. are also seen. Neurological symptoms are rarely seen.
Hemorrhagic and coagulopathies
1. Aplastic anemia and myelopathic diseases.
Aplastic anemia caused by various reasons is characterized by reduced bone marrow megakaryocytes and reduced platelet production. Platelet reduction can be the earliest manifestation of aplastic anemia, or it may be due to normalization of hemoglobin and granulocytes after treatment, but platelets have not yet been restored. In myelopathic diseases such as cancer infiltration, thrombocytopenia is mostly due to tumor cells damaging the giant nucleus fine leg, thus reducing platelet production. The above two cases can be clearly diagnosed by examining bone marrow, the former has low bone marrow proliferation and reduced megakaryocytes; the latter can be found in tumor cells.
2.Physical and chemical factors inhibit bone marrow.
Physicochemical factors such as ionizing radiation, alkylating agents, antimetabolites, cytotoxic agents, etc. are common complications in the treatment of malignant tumors, thrombocytopenia is a common complication, or direct poisoning of bone marrow cells, or rabbit epidemic reaction. Most of these factors cause diffuse damage to the bone marrow, and patients present with a decrease in whole blood. However, megakaryocytes are more sensitive to the effect of radiation in a few patients, as some patients may show only thrombocytopenia and megakaryocytopenia.
3. Factors that selectively inhibit megakaryocytes.
Chlorothiazides and their synergists can cause thrombocytopenia, in addition to the mechanism through the production of platelet antibodies, but also through the inhibition of platelet production. And the latter is more important. It is generally considered to be a pharmacological effect. Patients present with bone marrow depression and reduced megakaryocytes. Individual pregnant women taking this drug can cause congenital thrombocytopenia in the newborn, which can be asymptomatic in the mother.
4. Congenital megakaryocytopoiesis.
The disease is rare, with marked reduction in megakaryocytes and platelets, often accompanied by congenital malformations, such as kidney, heart, bone, etc. The prognosis is poor, and about 2/3 of affected children die of intracranial hemorrhage within 8 months. Maternal rubella during pregnancy and oral D860 can be factors in the development of the disease.
5. Other.
Estrogen can occasionally cause thrombocytopenia without megakaryocytes. Ethanol can inhibit platelet production, which is a long-term heavy alcohol consumption makes thrombocytopenia. There are few clinical manifestations of bleeding, and platelets can be restored after stopping alcohol consumption.
IV. Ineffective platelet production
The disease is common in some patients with megaloblastic anemia with vitamin B12 or folic acid deficiency, which is manifested as thrombocytopenia, some patients have bleeding tendency, and some show reduction of whole blood and normal or even increase of bone marrow megakaryocytes, so it is ineffective platelet production. With the treatment of megaloblastic anemia, platelets can return to normal.
V. Thrombopoietin deficiency
This disease is a thrombocytopenia due to congenital thrombopoietin deficiency. The disease is mostly hereditary, with bleeding manifestations starting in infancy, reduced platelet count, normal number of megakaryocytes, and no specific changes in morphology and structure.
VI. Periodic thrombocytopenia
This disease is a bleeding disorder caused by periodic thrombocytopenia of unknown cause. The disease is relatively common, with thrombocytopenia alternating with thrombocytosis or normal at regular intervals, usually 20 to 30 days apart. The disease is most common in women and its episodes often coincide with menstruation, with reduced platelets and increased bleeding during menstruation. Megakaryocytes generally do not decrease, and bleeding from the skin and mucous membranes is the main cause, with no specific treatment.
VII. Thrombocytopenia caused by spleen disease
Normally, 1/3 of platelets in the body are stagnated in the spleen. When there is splenomegaly such as portal hypertension, Gaucher’s disease, lymphoma, nodular disease, Folty syndrome, etc., the platelet count can be reduced, but the total amount of platelets in the body does not decrease. After epinephrine injection, the platelet count can be significantly increased within a certain period of time. Sometimes, there may be a factor of increased platelet destruction at the same time.
VIII. Infectious thrombocytopenia
This disease is a thrombocytopenic bleeding disorder caused by viral, bacterial or other infections.
1, viral infections: viral infections that can cause thrombocytopenia include measles, rubella, herpes simplex, chickenpox, cytomegalovirus infection, viral hepatitis, influenza, mumps, epidemic hemorrhagic fever, cat’s claw fever, dengue fever, etc.
Viruses can invade megakaryocytes and reduce platelet production. Viruses can also adsorb to platelets, resulting in increased platelet destruction; certain patients with severe measles and patients with epidemic hemorrhagic fever consume platelets due to diffuse intravascular coagulation.
2, bacterial infections: many bacterial infections can cause platelet reduction, including Gram-positive and negative bacteria caused by sepsis, such as meningococcal meningitis, Mycobacterium typhi, Mycobacterium tuberculosis. Bacterial toxins inhibit platelet production or increase platelet destruction, and may also increase platelet consumption due to toxins affecting vessel wall function.
In conclusion, in patients with simple thrombocytopenia, the disease is considered if there are clear signs of infection, and platelets recover when the primary infection is controlled.