The most common clinical manifestations of allergic purpura are bruises on the limbs, black stool, hematuria, and joint pain. It is mainly divided into articular, abdominal, cutaneous, renal, and mixed types. The presence of protein in the urine indicates kidney involvement, which means the condition is most severe. Allergic purpura generally can be alleviated with standard and active treatment, but recurrent attacks affecting the kidneys can lead to persistent purpuric nephritis and proteinuria that do not resolve.