Thrombocytopenic purpura (Verlhof disease) is a disease characterized by a tendency to bleeding due to thrombocytopenia (a decrease in platelet count in the blood up to 150 × 109 / L) with a normal or increased number of megakaryocytes in the red bone marrow.
Thrombocytopenic purpura is the most common disease from the hemorrhagic diathesis group. The incidence of new cases of thrombocytopenic purpura is 10 to 125 per million people per year. The disease, as a rule, manifests in childhood. Until the age of 10, the disease occurs with the same frequency in boys and girls, and after 10 years and in adults - 2-3 times more often in female patients.
In thrombocytopenic purpura, thrombocytopenia develops as a consequence of the destruction of platelets by means of immune mechanisms. Antibodies to their own platelets may appear 1-3 weeks after the virus or bacterial infections suffered, preventive vaccinations, taking medications for individual intolerance, hypothermia or insolation, after surgery, trauma. In some cases, it is not possible to identify any particular cause. Entered into the body antigens (for example, viruses, medicines, including vaccines) settle on the patient's platelets and induce an immune response. Antiplatelet antibodies are predominantly IgG. The reaction "Ag-AT" occurs on the surface of platelets. The lifetime of platelets loaded with antibodies in thrombocytopenic purpura is reduced to several hours instead of 7-10 days in normal. Premature death of platelets occurs in the spleen. Bleeding in thrombocytopenic purpura is caused by a decrease in the number of platelets, a secondary damage to the vascular wall due to the loss of angiotrophic function of platelets, a violation of the contractility of blood vessels due to a decrease in the concentration of serotonin in the blood, the impossibility of retraction of the blood clot.
The disease begins gradually or acutely with the appearance of hemorrhagic syndrome. The type of bleeding with thrombocytopenic purpura is petechial-spotted (bleeding). According to clinical manifestations, two variants of thrombocytopenic purpura are distinguished: "dry" - the patient only has skin hemorrhagic syndrome; "Wet" - hemorrhage in combination with bleeding. Pathognomonic symptoms of thrombocytopenic purpura - hemorrhages in the skin, mucous membranes and bleeding. The absence of these signs raises doubts about the correctness of the diagnosis.
Skin hemorrhagic syndrome occurs in 100% of patients. The number of ecchymoses varies from single to multiple. The main characteristics of cutaneous hemorrhagic syndrome with thrombocytopenic purpura are as follows. Inconsistency of severity of hemorrhage degree of traumatic impact; Perhaps their spontaneous appearance (mostly at night).
Polymorphism of hemorrhagic eruptions (from petechiae to major hemorrhages). Polychrome skin hemorrhage (color from purple to blue-green and yellow, depending on the prescription of their appearance), which is due to the gradual conversion of hemoglobin through intermediate stages of decay into bilirubin.
Often there are hemorrhages in the mucous membranes, most often tonsils, soft and hard palate. Possible hemorrhages in the tympanic membrane, sclera, vitreous, eye fundus. Hemorrhage in the sclera may indicate a threat of the most severe and dangerous complication of thrombocytopenic purpura - hemorrhage in the brain. As a rule, it arises suddenly and rapidly progresses. Clinically, cerebral hemorrhage is manifested by headache, dizziness, convulsions, vomiting, focal neurologic symptoms. The outcome of hemorrhage in the brain depends on the volume, localization of the pathological process, timeliness of diagnosis and adequate therapy.
Thrombocytopenic purpura is characterized by bleeding from the mucous membranes. Often they have a profuse character, causing severe posthemorrhagic anemia, which threatens the life of the patient. In children, bleeding from the mucous membrane of the nasal cavity is most common. Bleeding from the gingiva is usually less abundant, but they can become dangerous when extracting the teeth, especially in patients with undiagnosed disease. Bleeding after tooth extraction with thrombocytopenic purpura occurs immediately after the intervention and does not resume after its termination, in contrast to late, delayed hemorrhage in hemophilia. In girls puberty period, heavy meno- and metrorrhagia are possible. Gastrointestinal and renal bleeding are rare. There are no characteristic changes in the internal organs with thrombocytopenic purpura. Body temperature is usually normal. Sometimes tachycardia is detected, with auscultation of the heart - systolic murmur at the apex and at the Botkin point, weakening of the I tone caused by anemia. The increase in spleen is uncharacteristic and rather excludes the diagnosis of thrombocytopenic purpura.
With the course of acute acute (up to 6 months) and chronic (duration of more than 6 months) form of the disease. At the initial examination, it is impossible to establish the nature of the course of the disease. Depending on the degree of manifestation of the hemorrhagic syndrome, the blood indicators during the disease are divided into three periods: hemorrhagic crisis, clinical remission and clinical-hematological remission.