Sjögren's syndrome (SS) is a chronic inflammatory disorder characterized by diminished lacrimal and salivary gland function and associated with lymphocytic infiltration of exocrine glands, especially the lacrimal and salivary glands. In addition to causing dry eyes (keratoconjunctivitis sicca) and dry mouth (xerostomia), SS can affect extraglandular organ systems including the skin, lung, heart, kidney, neural, and hematopoietic systems.
Respiratory complications of SS include airway mucosal dryness (also known as xerotrachea), a variety of interstitial lung diseases (ILDs), non-Hodgkin lymphomas, pleural thickening or effusion, and, rarely, thromboembolic disease or pulmonary hypertension.
The clinical manifestations, evaluation, and diagnosis of interstitial lung disease in SS will be reviewed here. The clinical manifestations, classification, criteria for diagnosis, and pathogenesis of Sjögren's syndrome are presented separately. (See "Clinical manifestations of Sjögren's syndrome: Exocrine gland disease" and "Clinical manifestations of Sjögren's syndrome: Extraglandular disease" and "Classification and diagnosis of Sjögren's syndrome" and "Pathogenesis of Sjögren's syndrome".)
American-European criteria — The American-European criteria for the diagnosis of Sjögren's syndrome (SS) combine subjective symptoms of dry eye and dry mouth with objective signs of keratoconjunctivitis sicca and xerostomia (table 1). They were not developed for clinical practice and not every patient who receives a diagnosis of SS fulfills the proposed criteria. Diseases that can mimic SS and should be considered in the differential diagnosis of SS are included in the table (table 2). The diagnosis of SS is discussed separately. (See "Classification and diagnosis of Sjögren's syndrome", section on 'Classification criteria'.)
Primary Sjögren's syndrome — Primary Sjögren's syndrome (pSS) is diagnosed only when all other systemic rheumatic diseases are excluded; it predominantly affects women between 50 and 70 years of age. (See "Classification and diagnosis of Sjögren's syndrome", section on 'Primary SS'.)