Sjögren syndrome.

In 1933, the Swedish ophthalmologist Hendrik Sjögren was the first to suggest that behind the dryness that several of his patients presented, there could be a systemic disease related to an abnormal immune response. Since then, the term Sjögren's syndrome (SjS) has been used and it has been considered a minor and infrequent disorder compared to other systemic autoimmune diseases (SAD) and, consequently, with little progress both in clinical and therapeutic research. The emergence of new technologies at the end of the 20th century rapidly promoted the development of international projects of great impact and diffusion, which have completely changed this scenario, and in the last 20 years significant progress has been made in understanding the main epidemiological determinants and pathogenic mechanisms to increase the diagnostic accuracy and to design specific and individualized therapeutic strategies. Currently, SjS should be considered one of the most frequent SADs with an undoubtedly systemic phenotype beyond dryness, in which the identification of prognostic factors can allow personalized follow-up and, therefore, early therapeutic interventions that avoid severe, irreversible outcomes.