An approach to diagnosis and initial management of systemic vasculitis.

Systemic vasculitis occurs in a heterogeneous group of primary disorders or can be a manifestation of infection, an adverse drug reaction, malignancy or a connective tissue disease. A vasculitic process should be suspected in patients with unexplained ischemia or multiple organ involvement, especially when such features as polymyalgia rheumatica, inflammatory arthritis, palpable purpura, glomerulonephritis or multiple mononeuropathy are also present. The clinical features of systemic vasculitis depend on the organs involved and, in turn, organ involvement is largely influenced by the size of the affected blood vessels. The diagnostic work-up should be tailored to the clinical situation and geared toward a tissue or angiographic diagnosis, bearing in mind that the findings from these studies are not always pathognomonic. Emphasis should also be placed on exclusion of a secondary process. The diagnosis of the specific type of vasculitis may be made on the basis of the clinical features and the histopathologic or angiographic findings. Initial therapy for most types of systemic vasculitis consists of high-dose corticosteroids, with the addition of immunosuppressive therapy in certain patients.