Sjogren's syndrome is an autoimmune disease. Autoimmune diseases are characterized by the abnormal production of extra antibodies in the blood that are directed against various tissues of the body. This particular autoimmune illness features inflammation in certain glands of the body. Inflammation of the glands that produce tears (lacrimal glands) leads to decreased water production for tears and eye dryness. Inflammation of the glands that produce the saliva in the mouth (salivary glands, including the parotid glands) leads to dry mouth and dry lips.
Sjogren's syndrome with gland inflammation (resulting dry eyes and mouth, etc.) that is not associated with another connective tissue disease is referred to as primary Sjogren's syndrome. Sjogren's syndrome that is also associated with a connective tissue disease, such as rheumatoid arthritis, systemic lupus erythematosus, or scleroderma, is referred to as secondary Sjogren's syndrome.
What causes Sjogren's syndrome?
While the exact cause of Sjogren's syndrome is not known, there is growing scientific support for genetic (inherited) factors. The illness is sometimes found in other family members. It is also found more commonly in families that have members with other autoimmune illnesses, such as systemic lupus erythematosus, autoimmune thyroid disease, juvenile diabetes, etc. About 90% of patients with Sjogren's syndrome are female.
What are symptoms of Sjogren's syndrome?
Symptoms of Sjogren's syndrome can involve the glands, as above, but there are also possible affects of the illness involving other organs of the body (extraglandular manifestations).
When the tear gland (lacrimal gland) is inflamed from Sjogren's, the resulting eye dryness can progressively lead to eye irritation, decreased tear production, "gritty" sensation, infection, and serious abrasion of the dome of the eye (cornea). Dry eyes can lead to infections of the eyes.
Inflammation of the salivary glands can lead to mouth dryness, swallowing difficulties, dental decay, gum disease, mouth sores and swelling, stones and/or infection of parotid gland inside of the cheeks. Dry lips often accompany the mouth dryness.
Other glands that can become inflamed, though less commonly, in Sjogren's syndrome include those of the lining of the breathing passages (leading to lung infections) and vagina (sometimes noted as pain during intercourse recurrent vaginal infections).
Extraglandular (outside of the glands) problems in Sjogren's syndrome include joint pain or inflammation (arthritis), Raynaud's phenomenon, lung inflammation, lymph-node enlargement, kidney, nerve, and muscle disease. A rare serious complication of Sjogren's syndrome is inflammation of the blood vessels (vasculitis), which can damage the tissues of the body that are supplied by these vessels.
A common disease that is occasionally associated with Sjogren's syndrome is autoimmune thyroiditis (Hashimoto's thyroiditis), which can lead to abnormal thyroid hormone levels detected by thyroid blood tests. Heartburn and difficulty swallowing can result from gastroesophageal reflux disease (GERD), another common condition associated with Sjogren's syndrome. A rare disease that is uncommonly associated with Sjogren's syndrome is primary biliary cirrhosis, an immune disease of the liver that leads to scarring of the liver tissue. A small percentage of patients with Sjogren's syndrome develop cancer of the lymph glands (lymphoma). This usually develops only after many years with the illness. Unusual gland swelling should be reported to the physician.
How is Sjogren's syndrome diagnosed?
The diagnosis of Sjogren's syndrome involves detecting the features of dryness of the eyes and mouth. The dryness of the eyes can be determined in the doctor's office by testing the eye's ability to wet a small testing paper strip placed under the eyelid (Schirmer's test using Schirmer tear test strips). More sophisticated eye testing can be done by an eye specialist (ophthalmologist). Salivary glands can become larger and harden or become tender. Salivary-gland inflammation can be detected by radiologic nuclear medicine salivary scans. Also, the diminished ability of the salivary glands to produce saliva can be measured with salivary flow testing. The diagnosis is strongly supported by the abnormal findings of a biopsy of salivary-gland tissue.
The glands of the lower lip are often used to obtain a biopsy sample the salivary-gland tissue in the diagnosis of Sjogren's syndrome. The lower lip salivary-gland biopsy procedure is easily performed under local anesthesia with the surgeon making a tiny incision on the inner part of the lower lip to expose and remove a sample of the tiny salivary glands within.
Patients with Sjogren's syndrome typically produce a myriad of extra antibodies against a variety of body tissues (autoantibodies). These can be detected through blood testing and include antinuclear antibodies (ANAs), which are present in nearly all patients. Typical antibodies that are found in most, but not all patients, are SS-A and SS-B antibodies, rheumatoid factor, thyroid antibodies, and others. Low red blood count (anemia) and abnormal blood testing for inflammation (sedimentation rate) are seen.