The american college of rheumatology 1990 criteria for the classification of vasculitis. Summary - Fries, J F; Hunder, G G; Bloch, D A; Michel, B A; Arend, W P; Calabrese, L H; Fauci, A S; Leavitt, R Y; Lie, J T; Lightfoot, RW J (Arthritis Rheum, 1990)