Firstly, allergic purpura is a type of hypersensitivity reaction and also a specific type of vasculitis. The main triggering factors include infections, medications, and food allergies, among others. It is not curable and tends to recur. Allergic purpura can be categorized into skin type, joint type, abdominal type, renal type, and mixed type. The presence of black stool, hematuria, vomiting, or proteinuria often indicates abdominal or renal types, which are the most severe forms of allergic purpura. In cases of black stool and severe vomiting, it is crucial to eat timely, replenish fluids, and maintain electrolyte balance. Additionally, it is important to complete a mesenteric vascular ultrasound to check for mesenteric vascular embolism. Moreover, if hematuria and proteinuria occur, it is necessary to rest in bed and, if needed, perform a kidney biopsy to assess the extent of kidney damage. Allergic purpura can be life-threatening because if not treated promptly, it may lead to purpuric nephritis, which can cause symptoms like proteinuria, hematuria, and even hypertension and bodily edema. In severe cases, it may lead to renal failure and induce uremia, greatly harming health. Furthermore, children with allergic purpura may also develop serious complications such as intussusception, which can be life-threatening. If this condition is identified, surgical treatment should be administered promptly.