Update on childhood vasculitides

PURPOSE OF REVIEW: The purpose of this review is to provide an update on the new developments in pediatric vasculitis. RECENT FINDINGS: Because most childhood vasculitides are rare, few large systematic studies have been done. Studies of Henoch-Sch?nlein purpura have focused on pathogenesis and outcome. Genetic associations and molecular changes occurring during Henoch-Sch?nlein purpura, including cytokines, and endothelial and nitric oxide metabolism are discussed. Risk factors for renal involvement and poor renal outcome are described. Uncontrolled series of treatment protocols for severe Henoch-Sch?nlein purpura nephritis are mentioned. Several studies have focused on the pathogenesis of other primary vasculitides, especially polyarteritis nodosa. Series describing the clinical manifestations of childhood vasculitis and case reports of uncommon manifestations of vasculitis in children are presented. The efficacy of new therapies, including the use of thalidomide and biologic modifiers, has been shown in individual childhood cases; however, there are no controlled studies of these agents. SUMMARY: Besides studies of Henoch-Sch?nlein purpura, advances in pediatric vasculitis are few as a result of the rarity of most vasculitides in childhood. Multicenter collaboration is necessary to substantially increase the scientific base of investigating and treating childhood vasculitis.