1.Allergic purpura is mainly seen in children and adolescents, with low fever, headache, sore throat, fatigue and general discomfort 1 week-3 weeks before the onset of the disease. Most patients have purpura as the first symptom, but fever, abdominal pain and blood in stool, hematuria, angioneurotic edema, urticaria, etc. can also be the first symptom. If there is no purpura or rash, early diagnosis is difficult. For those who have arthralgia, change in urine, abdominal pain with few signs, they should be alert and pay attention to observation and follow-up to avoid missing the diagnosis. The diagnosis of purpura nephritis is mostly focal, and the prognosis is good for those who have combined purpura; a few of them are diffuse glomerular damage, which is difficult to distinguish from acute glomerulonephritis and lupus nephritis. If you are using corticosteroids, you can control the disease with large dose, and when the symptoms disappear, you can reduce the dose to small dose and maintain it for six months to one year, and a few need to maintain it for a longer time before stopping. If you can cooperate with western medicine treatment, you can play the strength of Chinese medicine to cure the root of anti-virus and regulate the immune imbalance, but also reduce the toxic side effects of western medicine hormone or immunosuppressant. 5, must emphasize the importance of removing the cause of the disease, the cause is not removed, will lead to repeated attacks. Among the causes, infection, especially upper respiratory tract infection, is the first; followed by food, such as milk, eggs, fish, shrimp, beans, crab, mushrooms and other products, if considered as allergic factors, before the complete cure of the disease, should be prohibited.