The standard skin, joint, and renal findings are used to diagnosis HSP. To make a diagnosis, throat cultures, urine, and blood tests for inflammation and kidney function are utilized. Vasculitis can be diagnosed by a biopsy of the skin or, less usually, the kidneys. HSP is often misdiagnosed because its symptoms are similar to those of other diseases. For example, people with HSP may also have arthritis, fever, pain, red marks on their skin, or problems with their sight or hearing. A doctor might call this syndrome "gouty arthritis," but it is actually vasculitis associated with the hereditary form of the disease. The word "vasculitis" means inflammation of the blood vessels. This means that there is damage to the blood vessels, which can lead to problems such as nerve damage, stroke, or failure of various organs such as the kidneys. People with HSP are mainly born with the mutation in one of the four genes that code for proteins involved in the immune system. Over time, these mutations cause the body to produce more of these proteins than normal, which leads to an overactive immune system. This overactivity causes small blood vessel walls to break down leading to inflammation. There are two types of HSP: Type 1 occurs most commonly in children and type 2 in adults. People with type 1 HSP will always experience pain and inflammation of the joints.