What is Sjögren syndrome?
Sjögren syndrome is an autoimmune disorder in which the body's immune system mistakenly reacts to the tissue in glands that produce moisture, such as tear and salivary glands. It is a chronic, inflammatory disease that often progresses to a more complex, systemic disorder that can affect other tissues and organs in the body such as joints, kidneys, and the intestinal tract. Sjögren syndrome is characterized by an unusual accumulation (infiltration) of a particular type of white blood cell, lymphocytes, in the glands that are responsible for fluid production.
The amount and quality of saliva and tears produced decreases with Sjögren syndrome, leading to a characteristic dry mouth and dry eyes that are referred to as "sicca syndrome." Other mucous membranes may also dry out. Those with this condition often have a feeling of sand or grit in the eyes, swollen salivary glands, difficulty swallowing, and a decreased sense of taste.
Sjögren syndrome can affect anyone at any age, but about 90% of those affected are women, the majority of whom are older than 40. According to the National Institute of Neurological Disorders and Stroke (NINDS), between 1 and 4 million people in the United States have Sjögren syndrome.
The Sjögren's Syndrome Foundation says that the average time to diagnose a symptomatic person can be more than six years. The disorder may present as primary Sjögren syndrome or as secondary Sjögren syndrome – a condition that coexists with other autoimmune disorders, such as systemic lupus erythematosus, polymyositis, scleroderma, or rheumatoid arthritis. Sjögren syndrome has also been associated with an increased incidence of lymphoma.