Mimics of primary systemic vasculitides

The primary systemic vasculitides are well defined entities, but a number of diseases can imitate their clinical, laboratory, radiographic and histological features. The importance of awareness and recognition of these conditions lies in the initiation of correct therapy for the specific disease process and in the avoidance of unnecessary and potentially harmful immunosuppression. In this review, we have provided a comprehensive, but by no means complete, review of some of the imitators of the primary vasculitides. Every attempt must be made to establish the diagnosis before indicated therapy is commenced. This will help to avoid therapeutic misadventures when managing patients with these complex diseases.