Small Vessel Vasculitides

There are two major groups of small vessel vasculitides: anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAVs) and immune complex vasculitides. AAVs are the most common small vessel vasculitis and have benefited the most from recent advances with large randomized control trials. Rituximab now plays an important role in both induction and maintenance treatment of this relapsing–remitting condition, and a greater focus on preventing damage from the disease and its treatment is important. Immune complex vasculitides are associated with immune complex deposition in the vasculature. They include antiglomerular basement membrane disease, which is rare and usually presents with pulmonary–renal syndrome, IgA vasculitis, the most common systemic vasculitis in children, and vasculitides secondary to systemic immune complex diseases.