Scientifically speaking there is no pattern to the occurrence of allergic purpura nephritis. The onset of allergic purpura is common in children under 10 years old and rare in adults (>20 years old). It occurs in the cold season and is more frequent in winter and spring. About 1/2 of the patients have a history of pioneer infections such as bacteria and viruses, and about 1/4 of the patients are related to fish and shrimp allergy or prophylactic injections and medications. Most patients have a benign, self-limiting process, and most heal within a few weeks. However, there are recurrent episodes or delays of several months or years, and about 50% of patients have recurrent episodes of the disease. The occurrence of purpura nephritis is mostly seen within 2 to 8 weeks after the occurrence of allergic purpura, a few months later, the incidence can be as high as 30% to 60%, individually seen before purpura or after 2 years or even years after purpura. The most common presentation is isolated hematuria. Proteinuria is mostly mild, but it can develop into massive proteinuria and manifest as nephrotic syndrome. In a few cases, acute deterioration of renal function may occur. Some patients may have hypertension and edema. Children with allergic purpura have four conditions that predispose them to kidney problems: 1. Those with more extra-renal symptoms early on. 2. Those with significant gastrointestinal symptoms. 3. Those with recurrent skin lesions appearing in batches. 4, Male, older children.