Allergic purpura is a common vasculitis related to hypersensitivity, essentially a type of vasculitis that belongs to hematological diseases. It is mostly caused by infections or allergies to food and drugs, predominantly occurring in adolescents. It is more common in males, but a minority of adults may also develop allergic purpura. The main types include abdominal, renal, articular, mixed, and cutaneous forms. However, when allergic purpura nephritis occurs, presenting with proteinuria or decreased kidney function, it is necessary to visit a nephrology department. Treatment should aim to control proteinuria, protect kidney function, and reduce damage to kidney functions. Therefore, it is essential to visit a nephrologist at this time. Allergic purpura must be differentiated in treatment; if it is merely a cutaneous or abdominal type, a hematologist can manage it. However, if the kidneys are involved, it requires consultation in a nephrology specialty. (Please use medications under the guidance of a professional physician and do not self-medicate.)