Necrotizing vasculitis--a 2009 update.

Necrotizing vasculitis continues to be a condition where difficult diagnostic and treatment decisions need to be made, with only a few well-done studies as clinical reference and support. New data suggest that both methotrexate and azathioprine may be effective agents for maintaining remission in antineutrophilic cytoplasmic antibody (ANCA)-associated vasculitis after remission is achieved with cyclophosphamide-based therapies. In addition, Behcet's syndrome appears to be more common than previously assumed and is likely more common than a combination of ANCA-associated vasculitis (AAV) syndromes.