Symptoms of thrombocytopenic purpura

Idiopathic (autoimmune) thrombocytopenic purpura is acute, chronic and recurrent. In acute form, the number of platelets is normalized (more than 150,000 / mm ³ ) within 6 months after diagnosis without recurrence. With a chronic form of thrombocytopenia, less than 150,000 / mm ³ lasts more than 6 months. With a recurring form, the platelet count decreases again after returning to normal. For children, the acute form is more typical, for adults it is chronic.

Due to the fact that idiopathic thrombocytopenic purpura often proceeds transiently, a true morbidity has not been established. The estimated incidence is about 1 per 10 000 cases per year (3-4 per 10 000 cases per year among children under 15).

Symptoms of acute and chronic idiopathic thrombocytopenic purpura

Clinical signs	Acute ITP	Chronic ITP
Age	Children 2-6 years old	Adults
Floor	Raleigh does not play	M / F-1: 3
Seasonality	Spring time	Raleigh does not play
Pre-existing infections	About 80%	Usually not
Associated autoimmune conditions (SLE, etc.)	Not typical	Characteristically
Start	Acute	Gradual
The number of platelets in mm 3	More than 20 000	40 000-80 000
Eosinophilia and lymphocytosis	Characteristically	Rarely
IgA level	Normal	Decreased
Antiplatelet antibodies	-	-
GpV	Often	No
Gpllb / llla	Rarely .	Often
Duration	Usually 2-6 weeks	Months and years
Forecast	Spontaneous remission in 80% of cases	Unstable continuous flow

As mentioned above, the pathogenesis of idiopathic thrombocytopenic purpura is the increased destruction of platelet-loaded autoantibodies by cells of the reticulogistiocytic system. In experiments with labeled platelets it was established that the life span of platelets decreased from 1-4 hours to several minutes. The increase in the content of immunoglobulins (IgG) on the surface of platelets and the frequency of destruction of blood platelets in idiopathic thrombocytopenic purpura are proportional to the level of platelet-associated IgG (PAIgG). The targets for autoantibodies are the glycoproteins (Gp) of the platelet membrane: Gp Ilb / IIIa, Gp Ib / IX and GpV.

People with HLA phenotype B8 and B12 have an increased risk of developing the disease if they have precipitating factors (antigen-antibody complexes).

The peak incidence of idiopathic thrombocytopenic purpura falls to the age of 2 to 8 years, with boys and girls being sick with the same frequency. In children younger than 2 years (infantile form), the disease is characterized by a sharp onset, severe clinical course with the development of deep thrombocytopenia of less than 20,000 / mm ³, poor response to the effect and frequent process chronication - up to 30% of cases. The risk of debilitating chronic idiopathic thrombocytopenic purpura in children is also increased in girls older than 10 years with a duration of the disease more than 2-4 weeks before the diagnosis is made and the number of platelets is more than 50,000 / mm ³.

In 50-80% of cases, the disease occurs 2-3 weeks after an infectious disease or immunization (smallpox, live measles vaccine, etc.). Most often, the onset of idiopathic thrombocytopenic purpura is associated with nonspecific infections of the upper respiratory tract, approximately 20% of cases are specific (measles rubella, measles, chicken pox, whooping cough, mumps, infectious mononucleosis, bacterial infections).

Differences between chronic infantile and chronic pediatric idiopathic thrombocytopenic purpura

Symptoms	Chronic infiltile NEHL	Chronic children's ITP
Age (months)	4-24	More than 24
Boys / girls	3: 1	3: 1
Start	Sudden	Gradual
Previous infections (viral)	Usually not	Often
The number of platelets in the diagnosis, in mm 3	More than 20 000	40 000-80 000
Response to treatment	Bad	Temporary
Frequency of total morbidity,%	Thirty	10-15

Symptoms of idiopathic thrombocytopenic purpura depend on the severity of thrombocytopenia. Hemorrhagic syndrome manifests itself in the form of multiple petechial-bronchial rashes on the skin, hemorrhages on the mucous membranes. Since petechiae (1-2 mm), purpura (2-5 mm) and ecchymosis (more than 5 mm) can also accompany other hemorrhagic conditions, the differential diagnosis is based on the number of platelets in the peripheral blood and the duration of bleeding.

Bleeding appears when the number of platelets decreases to less than 50,000 / mm ³. The threat of serious bleeding occurs with a deep thrombocytopenia of less than 30,000 / mm ³. At the beginning of the disease, nasal, gingival, gastrointestinal and renal bleedings are usually uncharacteristic, rarely vomiting coffee grounds and melena. Severe uterine bleeding is possible. In 50% of cases, the disease manifests itself in the tendency to form ecchymoses in the places of bruises, on the front surface of the lower limbs, over the bony protrusions. Deep muscle hematomas and hemarthroses are also not characteristic, but may be the result of intramuscular injections and extensive injuries. With deep thrombocytopenia, hemorrhages occur in the retina of the eye, rarely bleeding into the middle ear, leading to a decrease in hearing. Hemorrhage in the brain occurs in 1% of cases with acute idiopathic thrombocytopenic purpura, in 3-5% - with chronic idiopathic thrombocytopenic purpura. Usually it is preceded by headache, dizziness and acute bleeding of any other localization.

At an objective inspection at 10-12% of children, especially early age, it is possible to reveal splenomegaly. In this case, a differential diagnosis is made with leukemia, infectious mononucleosis, systemic lupus erythematosus, hypersplenism syndrome. Enlargement of lymph nodes with idiopathic thrombocytopenic purpura should not occur, unless it is associated with a viral infection.

Secondary thrombocytopenic purpura

As mentioned earlier, thrombocytopenia can be idiopathic or secondary as a result of a number of known causes. Secondary thrombocytopenia, in turn, can be divided depending on the number of megakaryocytes.

Thrombopoietin deficiency

A rare congenital cause of chronic thrombocytopenia with the appearance of numerous immature megakaryocytes in the bone marrow is a deficiency of thrombopoietin.

Treatment consists of plasma transfusions from healthy donors or patients with idiopathic thrombocytopenic purpura, which leads to an increase in the number of platelets and the appearance of signs of maturation of megakaryocytes, or the substitution of thrombopoietin.