Allergic Purpura, also known as Henoch-Schonlein Purpura (HSP), is a type of blood vessel inflammation that causes purple spots or skin rash on the body. There are various synonyms or alternative terms used for this condition, such as IgA Vasculitis, Anaphylactoid Purpura, and Schonlein-Henoch Syndrome. These names describe the same type of disease, and they all imply that HSP is a result of an allergic reaction or immune system disorder. Symptoms of HSP may include joint pain, abdominal pain, blood in urine, and swelling of the hands and feet. Treatment usually involves anti-inflammatory medication and managing any underlying conditions that may have triggered the allergic reaction.