Allergic purpura, one of the most common vasculitis in adolescents and children, is a class of vascular metaplasia hemorrhagic disease, with hemorrhagic rash, arthralgia, abdominal pain, gastrointestinal bleeding and nephritis as the main clinical manifestations, the incidence of purpura nephritis in allergic purpura is about 34.2%-49%, which determines the prognosis of allergic purpura. Allergic purpura is very easy to be delayed and recurrent, and the use of Chinese and Western medicines in the treatment plays a vital role. The cause of allergic purpura: At present, it is thought to be related to infection and allergic reaction, only a few patients can find the exact allergen. 1/3-2/3 patients have upper respiratory tract infection before the onset, but lack of etiological evidence, various infections can induce HSP, including bacteria, virus, chlamydia and parasites. In addition, cold, drug and food allergies, mites, pollen, fungi, and mosquito bites can also trigger the onset of the disease. Allergic purpura is also a kind of allergic reaction disease, including genetic predisposition, allergic constitution and environmental disorders in human body. 2, the incidence and time of purpura nephritis: the incidence of proteinuria and/or hematuria in patients with allergic purpura is close to 50%, 1/5 of them show nephrotic syndrome, individual children will have acute renal insufficiency, if they do not receive regular treatment, the proportion of allergic purpura finally progressing to chronic renal failure is around 5%. Renal damage occurs within 4 weeks in 85% of cases, within 6 weeks in 91%, and within 6 months in 97%. Therefore, even if the starting urine test is normal, it is still necessary to check continuously for 6 months, and gradually extend the interval between tests until the end of one year. 3, daily precautions for allergic purpura: avoid wearing tight shoes and socks, avoid sports activities during the acute period, avoid contact with clearly allergic substances and foods according to the allergen test results, avoid contact with oil fumes, house dust, pollen, formaldehyde, etc. in life, and do protection on hazy days; pay attention to the monitoring of skin, gastrointestinal tract, nervous system, lung, testis and other complications; prevent infection, such as bacterial infection, viral infection or parasitic infections, etc. 4, allergic purpura of western medicine treatment: there are clear infection factors can be anti-infection treatment; anti-group anti-allergy treatment, can use rutin, vitamin C, calcium, anloin or hemostasis, etc., serious skin damage or joint type, abdominal type, renal purpura can be short-term moderate use of glucocorticoids, part of the recalcitrant chronic nephritis patients, can choose cyclophosphamide or azathioprine. The Chinese medicine treatment of allergic purpura: This disease is called “purpura”, “purpura”, belongs to the Chinese medicine blood evidence category, divided into wind-heat wounded complex evidence, yin deficiency fire evidence, blood-heat stasis poison evidence, damp-heat contained evidence, gas does not take blood evidence several types, can be given The treatment can be given to clear heat, detoxify and cool the blood to dispel wind (Yin Qiao San combined with Xiao Feng San plus or minus), nourish Yin, lower fire and cool the blood to stop bleeding (Zhi Bai Di Huang Tang combined with Er Zhi Wan plus or minus), clear heat, cool the blood, resolve blood stasis and detoxify the toxin (Rhizoma Rhizoma Rhizoma Di Huang Tang combined with Rhizoma Rhizoma Rhizoma Di Huang Tang plus or minus), clear heat, dampness and cool the blood to resolve blood stasis (Si Miao Wan combined with Rhizoma Rhizoma Rhizoma Di Huang Tang plus or minus), and tonify Qi, strengthen the spleen and regulate blood to resolve blood stasis (Gui Shen Tang combined with Huang Qi Gui Zhi Wu Wu Wu Wu Tang plus or minus).