Henoch-Schonlein Purpura is caused by allergy. When some allergens enter allergic constitution, after a incubation period of about two weeks, allergic inflammation will occur in capillaries, which will increase the permeability of capillaries, and blood and lymph will penetrate into tissues, causing exudative bleeding and edema in subcutaneous mucosa or visceral tissues. Thrombocytopenic purpura may be related to autoimmunity, and the decrease of platelets affects hemostasis function, which is also one of the reasons.
In addition, there are the following differences between allergic purpura and thrombocytopenic purpura, which are described in detail as follows.
First, the clinical manifestations are different
Henoch-Schonlein purpura
Most children had a history of upper respiratory tract infection 1-3 weeks before onset, and skin purpura was the first symptom in most cases, and rash was the main manifestation of the disease. Mainly distributed in the weight-bearing parts, mostly at the distal end of lower limbs, densely around the ankle joint; Secondly, it is seen in the buttocks.
The characteristic rash is higher than the skin, and it is small urticaria or pink maculopapular rash at first, and it is purpura if it is pressed. Hemorrhagic blisters, even necrosis, can also be formed at the lesion site, resulting in ulcers. Purple merged into pieces and finally turned brown. Generally, it disappears within 1-2 weeks, leaving no trace; It can also be postponed for weeks or months.
About 2/3 children have digestive tract symptoms. It usually occurs within 1 week of rash. The most common symptom is abdominal pain, mostly manifested as paroxysmal periumbilical colic, which can also spread to any part of the abdomen. About half of the children are positive for occult blood in stool, and some children have bloody stools or even hematemesis.
Urinary system can be gross hematuria or microscopic hematuria and proteinuria, or tubular urine. It can occur at any stage of the course of allergic purpura, but most of them appear 2-4 weeks after purpura, and can also appear after the rash subsides or the disease is at rest. Most children have only a few joint pains or arthritis.
? Thrombocytopenic purpura
This disease is found in children of all ages, and can be divided into acute (≤6 months) and chronic (> 6 months) two types.
Acute onset is sudden, bleeding is severe, and respiratory tract infection often occurs shortly before or at the same time of bleeding. Chronic cases have no obvious peak age, but most of them are in school age. Most of them have hidden onset and mild bleeding symptoms. About 10% of the children change from acute to chronic. Its bleeding is characterized by extensive bleeding of skin and mucosa, mostly scattered needle-like intradermal or subcutaneous bleeding points, forming petechiae or ecchymosis; There are many limbs, but they can also be systemic bleeding spots or hematomas; Some children complain of epistaxis (about 20%-30%) or gingival bleeding.
Common hematemesis or melena are mostly caused by swallowing when the mouth and nose are bleeding, and it is rare to have real gastrointestinal bleeding. Subconjunctival hemorrhage is also a common symptom. About 1% children have intracranial hemorrhage, which is the main cause of death in thrombocytopenic purpura.
Second, the laboratory examination results are different.
Henoch-Schonlein purpura
Platelet count is normal or elevated. The bleeding time, coagulation time and blood clot contraction time are all normal. In some children, the total number of white blood cells increased as high as 20× 109/L, accompanied by nuclear shift to the left. The erythrocyte sedimentation rate can be accelerated, and C-reactive protein and anti-streptolysin can be positive.
? Thrombocytopenic purpura
(1) Blood routine: The most important change in peripheral blood is the decrease of platelets below 100× 109/L, and the degree of bleeding is directly proportional to the level of platelets. The other two lines are basically normal, with occasional hemorrhagic anemia.
(2) Bone marrow smear: The main manifestation is megakaryocyte maturation disorder. Classification of megakaryocytes: the percentage of protomegakaryocytes and immature megakaryocytes is normal or slightly higher; The number of mature megakaryocytes without platelet release increased significantly, reaching 80%. However, mature megakaryocytes that release platelets are rare.
(3) Platelet antibody test: The main reason is the increase of platelet surface IgG(PA IgG), and the positive rate is 66%- 100%. Simultaneous detection of anti-platelet antibodies (PAIgG, PAIM, PAIgA) can improve the positive rate.
Third, the treatment plan is different.
? Henoch-Schonlein purpura
Use antihistamines and calcium when you are in bed rest at acute stage and have urticaria or angioneurotic edema. Antiplatelet drugs (aspirin or dipyridamole) and anticoagulant therapy (heparin sodium or heparin calcium) can be used. When there are serious gastrointestinal diseases (such as gastrointestinal bleeding), nephrotic syndrome and acute nephritis, glucocorticoid can be used for treatment. When renal failure occurs, plasma exchange and dialysis can be used, and severe cases can be treated with large dose of gamma globulin.
? Thrombocytopenic purpura
Reduce activities and avoid trauma. Glucocorticoid is used for treatment, and gamma globulin can be used for children with severe bleeding or above. Transfusion of fresh platelets can only be used as an emergency treatment for severe bleeding. Immunosuppressants such as vincristine and cyclophosphamide can be tried if the hormone is ineffective. Splenectomy has a certain remission rate for chronic children, but the surgical indications should be strictly controlled.
The above are the main differences between allergic purpura and thrombocytopenic purpura. A comprehensive understanding of these can accurately distinguish and scientifically treat them.
However, it should be noted that these two diseases have a long recovery period. During this period, we must pay special attention to related life care, such as strengthening nutrition, moderate exercise, ensuring adequate sleep, etc., to promote disease recovery.