Vasculitis in the connective tissue diseases.

Vasculitides in the setting of connective tissue diseases are generally thought to be infrequent and relatively little is written about them. They are, however, important both because they may pose diagnostic and therapeutic challenges and affect prognosis. In each of the connective tissue diseases, vasculitis can present in various clinical and pathologic forms adding to their diagnostic and therapeutic difficulties. This article reviews recent information on the frequency, characteristics, and possible pathogenic mechanisms of the vasculitides occurring in patients with the main connective tissue diseases.