Vasculitis associated with connective tissue disorders.

This article focuses on the important association of vasculitis with the connective tissue diseases. The immunopathologic mechanisms in these secondary vasculitides, with complement and immune-complex involvement, differ from those involved in primary systemic necrotizing vasculitis even though histologically the lesions may appear identical. Any size of vessel may be involved, so biopsy evidence of small vessel disease does not exclude arterial lesions elsewhere. The clinical manifestations are equally wide ranging and vary from one connective tissue disease to another. Treatment of vasculitis is generally with immunosuppressive agents but is dependent on the degree and severity of the vasculitis. There is an important need to make a distinction between vasculopathy, where there is no evidence of underlying inflammation, and true vasculitis because the former requires anticlotting therapy rather than immunosuppression.