Vasculitis: a collection of pearls and myths.

Since Kussmaul and Maier described the index case of vasculitis in 1866, the field has seen many changes. What was considered for decades to be only a single disorder is now known to consist of at least 15 to 20 distinct conditions. Important strides have been made in unraveling the pathophysiology of some individual forms of vasculitis, but many mysteries remain. Over time, numerous myths and occasional pearls have arisen from the care of patients with these disorders. This collection of pearls and myths gathers lessons about the status of clinical care of vasculitis patients in the year 2008.