Allergic purpura, a capillary allergic disease, is a common disease in childhood, especially in school-age children, mostly in spring and autumn, more in boys than in girls. In recent years, the incidence of allergic purpura has a tendency to increase. It is generally believed that the allergic factors that cause capillary metaplasia may include infections such as bacteria, viruses and parasites; foods such as milk, eggs, fish and shrimp; drugs such as antibiotics, sulfonamides, antipyretics and sedatives; and pollen. Insect bites and vaccinations, etc. These factors can cause some human organisms to have metamorphic reactions. As a result of the deposition of antigen-antibody complexes in the blood vessel wall, causing the permeability of the blood vessel wall to increase, a large number of red blood cells to the outside of the blood vessels and the onset of disease. Most children have a history of upper respiratory tract infection 1 to 3 weeks before the onset of allergic purpura. The clinical manifestations often appear first in the lower extremities of the calves, anterior tibial, gastrocnemius and ankle, and are basically symmetrical on both sides, starting as small pinpoint-like red dots, gradually expanding and fusing with each other. In mild cases, the bleeding dots may be slightly higher than the skin surface and do not discolor when pressed, with a slight itching or swelling sensation, and are generally not painful. In addition, the disease can involve the skin, gastrointestinal, joints and kidneys, causing the corresponding clinical symptoms, serious cases can not only cause gastrointestinal bleeding, but also cause kidney function damage, which is not alarming. Therefore, once diagnosed, children’s allergic purpura must be treated promptly. The actual fact is that you will be able to find out the cause of the problem. For those who are infected, you should actively look for the infected lesion into 1z-JJ.-/. Furuncle. Discontinue all suspected allergic drugs and foods and avoid contact with suspected allergens. If you suspect that food allergy is caused, you should actively look for possible allergenic food, and do not have chicken, duck, fish, shrimp, milk and all kinds of meat in your food. After treatment purpura disappears 1 month before resuming animal protein diet, the principle of resuming is to add animal protein containing diet one by one gradually, add one kind for 3 days, and add the second and third kind after eating without allergic reaction. This ensures safety and facilitates the discovery of what kind of food is causing the allergy. As viral or bacterial infections can lead to recurrence of purpura, generally after 3 months of treatment the situation is stable, the chances of recurrence in the future will be rare. If the purpura stays untreated for more than 3 months, the probability of recurrence will increase. Therefore, during the treatment period, the child should not go to crowded and air polluted environment, avoid strenuous exercise, excessive fatigue, eliminate the opportunity of infection, avoid contact or eat food that may cause allergy. Finally, parents should also supervise their children to take medication on time and follow the doctor’s instructions for regular review. 2.Anti-allergic drugs In the acute stage, anti-allergic treatment should be carried out, paracetamol, Xyosmin, Keminan and other anti-allergic drugs can be used, if necessary, a large amount of vitamin C intravenous infusion can be added. 3.Hormone and immunosuppressant Hormone is effective for joint pain, abdominal pain, blood in stool and neurotic edema, but it cannot reduce the occurrence of purpura and kidney damage, nor can it prevent recurrence. Generally, during the acute attack period, prednisone 1 to 2 mg per kg of body weight per day, divided into 3 doses, and the drug can be stopped after the symptoms are relieved. If the complication of nephritis and hormone therapy is ineffective, cyclophosphamide can be added to the patient in mild cases in 7 to 10 days to heal, serious cases are up to weeks to months, but the vast majority of patients have a good prognosis. 4, prevention of allergic children should not have pets, minimize contact with animal fur; children with clear allergens should avoid contact with or eating these allergens; usually pay attention to climate change, timely increase and decrease clothing, prevent colds, regular ventilation in the room; pay attention to dietary hygiene, wash hands regularly, do not eat unclean fruits and fruits and aquatic plants to eliminate the opportunity of intestinal parasitic infections; strengthen exercise, improve the body’s immunity to various infections. Improve the immunity of the body to various infections. In addition, before the disease is cured, the child should not be vaccinated, and only after the disease has been cured for 3-6 months should vaccination be given, otherwise the disease may be induced to recur.