Allergic purpura is very likely to damage the kidneys of children, usually within about a month after the disease involves the kidneys and leads to purpura nephritis, which usually manifests as symptoms of hematuria visible to the naked eye or microscopic hematuria and proteinuria, and this disease is mostly found in children. So, how to treat purpura nephritis when a child has it, must we do a kidney puncture? Do you have to use hormones to treat all purpura nephritis? The most important thing is to make sure that you have a good understanding of the situation. If the child has only microscopic hematuria and the microscopic red blood cell count is 3-5/HP, he can be treated with anticoagulant and microcirculation improving drugs such as Pansentin and Polyclonal, and regular follow-up can be observed, excessive treatment (such as the application of hormones, etc.) will bring more side effects and the effect is not good; if the child has proteinuria, ACEI/ARB drugs (i.e. common Pulley, Sartan, etc.) can be used, which can protect the kidney and reduce urine protein. Dr. Jin added that although these drugs are commonly used clinically for the treatment of hypertension, as long as the therapeutic dose is well mastered applied to children with kidney disease will rarely cause hypotension. Children with purpura kidney with 24-hour urine protein greater than 250mg, then need to apply glucocorticoid therapy, if the kidney puncture pathological stage in grade IIB or above, then to be combined with immunosuppressive drugs. For those parents who have concerns and do not want to do renal puncture, they should inform the family as much as possible that the test is a mature and routine technique to dispel their concerns, and for those who really do not want to do renal puncture, they can be treated with sufficient amount of hormone alone for 2-3 weeks for observation, and if the decrease of urine protein is not significant, immunosuppressants should be added in time; although immunosuppressants have more side effects (such as liver damage, bone marrow suppression and increase the chance of infection), the Hormone therapy alone will take longer and require larger doses of hormones and is likely to cause other complications related to allergic purpura, and severe purpura nephritis may even cause interstitial renal changes. Which patients need shock therapy? Shock therapy is a treatment with high doses of hormones administered intravenously and is one of the most effective and convenient ways to rapidly control disease progression. If the child has severe symptoms, such as acute nephritis, with a grade 4-5 renal puncture pathology and a microscopic crescent of 70% or more, he should be treated with methylprednisolone shock therapy, which is often administered for three days at a dose of 15-30 mg per kg of body weight per day, followed by observation of the effect. Once a month, but in view of the side effects of cyclophosphamide, primidone is currently used in clinical practice. Dr. Jin added that the pathological examination is very important for the choice of shock therapy. Some children may have high proteinuria, but the pathological classification is low, and the oral hormone control is very effective, so shock therapy is not necessary. If the child’s renal function continues to deteriorate, with symptoms such as abdominal pain and gastrointestinal bleeding, and if high-dose methylprednisolone shocks combined with immunologic agents are not effective, plasma exchange is indicated. This method involves drawing out the child’s blood, separating the plasma and supplementing it with a certain amount of plasma from a healthy person or other surrogates, which has a good immediate therapeutic effect. However, the side effects of plasma replacement are relatively large, such as severe allergy, hypotension and infection, etc. It is generally not the first choice of treatment, and I personally believe that it should only be used when shock therapy is not effective. What tests are needed for follow-up of children with purpura nephritis? Children in the progressive stage of purpura nephritis need to be hospitalized, while those with mild disease can be followed up in the specialist outpatient clinic, usually 5-7 days after the first medication, to do 24h urine protein, urine routine and renal function tests in order to assess the efficacy. The dosage of oral hormones should be gradually reduced according to the recovery. If immunosuppressive drugs are used, different tests should be selected according to the drug regimen. For example, only routine blood tests are needed for primaquine, while routine blood tests and liver function tests are needed for cyclophosphamide and azathioprine, so fasting is required during the tests. Is urine occult blood a relapse of the disease? Purpura nephritis is well controlled, but the urine occult blood check always has 2-3 plus signs, which is a very common problem in clinical treatment. Dr. Jin explained, if only urine occult blood generally do not need to worry excessively, such as microscopic examination of 6-7 red blood cells as long as continuous observation, generally speaking, urine occult blood lasts longer, may have six months to a year; also can use some conservative treatment methods, such as the use of some anticoagulants, drugs to improve microcirculation; on the contrary, the application of hormones and immunosuppressants and other active treatment will instead bring more side effects, which is not worth the loss.