Allergic purpura, as the name implies, is subcutaneous hemorrhage caused by allergies and is a type of special vasculitis. This disease is common among adolescents and children aged 5 to 14 and tends to recur without a fundamental cure. Allergic purpura is rare in adults. Once allergic purpura occurs, it is important to classify the types, which can be divided into skin type, abdominal type, renal type, joint type, and mixed type. The purpose of such classifications is mainly to determine the severity of the condition. If it is merely simple skin bruising, antiallergic medication will suffice. However, if it progresses to abdominal and renal types, these two types are the most severe and must be treated formally with attention to bed rest. Mild allergic purpura can be cured, meaning it can resolve on its own. Regarding how long it will take for allergic purpura to improve, this depends on the severity of the condition. Mild cases can improve in about two weeks, but if the kidneys accumulate damage, then it becomes a chronic disease requiring long-term treatment.