<prompt> Answer this question truthfullyCan you provide an overview of Henoch-Schönlein purpura?  <response>: <reason> Henoch-Schönlein purpura should be differentiated from other immune complex mediated small vessel vasculitis such as Anti-glomerular basement membrane disease, Cryoglobulinemic vasculitis, Hepatitis C virus-associated cryoglobulinemic vasculitis, Hypocomplementemic urticarial vasculitis anti-C1q vasculitis. 