Churg-Strauss synrome (also known as allergic granulomatosis) is a medium and small vessel autoimmune vasculitis, leading to necrosis. It involves mainly the blood vessels of the lungs (it begins as a severe type of asthma), gastrointestinal system, and peripheral nerves, but also affects the heart, skin and kidneys. It is a rare disease that is non-inheritable, non-transmissible and often mis-diagnosed. Churg-Strauss syndrome was once considered a type of Polyarteritis nodosa (PAN) due to their similar morphologies.