Long‐term risk of mortality and lymphoproliferative disease and predictive classification of primary Sjögren's syndrome

In patients with primary SS, 1 in 5 deaths is attributable to lymphoma. The presence of palpable purpura and low C4 levels at the first visit adequately distinguishes high-risk patients (type I primary SS) from patients with an uncomplicated disease course (type II [low-risk] primary SS).