Henoch-Schönlein Purpura (HSP) is a small-vessel vasculitis that primarily affects children. It is characterized by a distinctive rash, often appearing as purple spots or bruises on the skin, particularly on the buttocks and legs. HSP can also cause joint pain, abdominal pain, and kidney involvement, leading to symptoms like blood in the urine. The exact cause of HSP is not well understood, but it is often preceded by an upper respiratory infection. Most cases are mild and resolve on their own, although some children may require treatment to manage symptoms or complications.