There are effective treatments for vasculitis if it is caught before there is major tissue damage. The causes of most kinds of vasculitis are unknown.
The inflammation of blood vessels is the body's immune response, but to what? Doctors don't know what the body is responding to, only that the reaction is "hyperactive," or exaggerated.
Once treated, doctors cannot predict whether vasculitis will come back. For this reason vasculitis that has been treated and is under control is not called "cured" but rather "in remission." Vasculitis may flare up due to medication changes or if there is a flare of an associated infection.