Sjögren syndrome and mixed connective tissue disease

Patients with Sjögren syndrome and mixed connective tissue disease (MCTD) often present to dermatologists because of their frequent cutaneous manifestations. Patients with Sjögren syndrome can develop cutaneous vasculitis, which is associated with a higher risk of lymphoma and severe internal organ manifestations. Cutaneous complications in MCTD include livedoid vasculopathy, cutaneous vasculitis, and calcinosis cutis. Digital gangrene can occur in Sjögren syndrome as well as in MCTD, as a complication of not only cutaneous vasculitis but also recurrent attacks of Raynaud phenomenon or as a part of the associated antiphospholipid antibody syndrome. This chapter discusses the complications arising out of cutaneous involvement in Sjögren syndrome and MCTD, and their management.