Sjögren's Syndrome (SS) pronounced 'show-grins', is one of the most common and least diagnosed rheumatic diseases. In some patients, it presents as only vague symptoms of dry mouth and irritated eyes, while in others it is associated with severe systemic illness and autoimmunity and may even terminate in lymphoid malignancy.
SS is an autoimmune disease which immune cells infiltrate and destroy the glands which produce tear and saliva, resulting in dryness of the eyes and mouth.
There is no known cause for Sjögrens syndrome, but it is suspected that several factors are involved. These factors include infectious (viral), hormonal, genetic and stress. Currently, it is suspected that one or more viruses play a role. Stress may be involved acting through psychoneuro-immunologic mechanisms.
Basic clinical features
SS is a chronic autoimmune and inflammatory disease characterised by diminished lacrimal (eyes) and salivary gland secretion (sicca complex) resulting in dry eyes and dry mouth.
Objective evidence of the sicca complex in a patient who shows no signs of rheumatic disease is sufficient for a diagnosis primary SS.
Two presentations are common. One is the rapid development of severe oral and ocular dryness, which is often accompanied by episode parotid swelling in an otherwise well patient. The other is the insidious and slowly progressive development of sicca complex in a patient with rheumatoid arthritis (RA).
The connection between Sjögren's and Lupus
Sjögren's Syndrome (SS) and systemic lupus erythematosus (SLE) both belong to the connective tissue disease class of rheumatic diseases. While they both share a couple of genetic, clinical and serologic markers, they have their own distinctive characteristics, marking the clinical diagnosis by the rheumatologist rather feasible.
Few patients with SS will develop SLE. Contrarily, approximately 25% of patients with SLE will develop SS in the course of the disease, SLE appears to be more prevalent in women of childbearing age, and SS is more prevalent on women with an average age of 50.
Viral infection, Epstein Barr virus, or an HIV-like virus (not HIV itself) may lead respectively to primary SS in which the glandular structures like parotid glands are polarised or to SLE in which basement membrane of the kidneys or skin is polarised.
Sjögren's Syndrome and the Eye
The most frequent eye complaint is the sensation of a foreign body in the eye, which patients describe as a "gritty" or "sandy" feeling. Other ocular symptoms include accumulation of thick "ropey" strands in the eyes, particularly upon wakening; decreased tearing; redness; burning; light sensitivity; eye fatigue; itching; and a "filmy: sensation that interferes with vision. Ocular complications include corneal ulceration, vascularization (formation of new blood vessels) and opacification (diminished ability to see), followed rarely by perforation. Many patients are able to treat problems symptomatically. Others are forced to cope with blurred vision and constant eye discomfort.