Sjögren's syndrome

Sjögren's Syndrome 

Definition

Sjögren's syndrome (SS) is a disorder in which the mouth and eyes become extremely dry. Sjögren's syndrome is often associated with other autoimmune disorders. It is named for Henrik Sjögren, a Swedish ophthalmologist.

Description

Like other autoimmune disorders, Sjögren's syndrome occurs when the body's immune system mistakenly begins treating parts of the body as foreign invaders. While the immune cells should attack and kill invaders like bacteria, viruses, and fungi, these cells should not attack the body itself. In autoimmune disorders, however, cells called antibodies see tissues of the body as foreign, and help to start a chain of events that results in damage and destruction of those tissues.

There are three types of Sjögren's syndrome. Primary Sjögren's syndrome occurs by itself, with no other associated disorders. Secondary Sjögren's syndrome occurs along with other autoimmune disorders, like systemic lupus erythematosus, rheumatoid arthritis, scleroderma, vasculitis, or polymyositis. When the disorder is limited to involvement of the eyes, with no other organ or tissue involvement evident, it is called sicca complex.

Women are about nine times more likely to suffer from Sjögren's syndrome than are men. SS affects all age groups, although most patients are diagnosed when they are between 40 and 55 years old. Sjögren's syndrome is commonly associated with other autoimmune disorders. In fact, 30% of patients with certain autoimmune disorders will also have Sjögren's syndrome.

SS is found in all races and ethnic groups. It is thought to affect between 0.1% and 3% of the population in the United States; this range reflects the lack of a uniform set of diagnostic criteria. According to the American College of Rheumatology, between 1 million and 4 million Americans have Sjögren's syndrome.

Causes and symptoms

The cause of Sjögren's syndrome has not been clearly defined, but several causes are suspected. The syndrome sometimes runs in families. Other potential causes include hormonal factors (since there are more women than men with the disease) and viral factors. The viral theory suggests that the immune system is activated in response to a viral invader, but then fails to turn itself off. Some other immune malfunction then causes the overly active immune system to begin attacking the body's own tissues. In 2004 a group of Greek researchers presented evidence that a coxsackievirus may be the disease organism that triggers SS.

The main problem in Sjögren's syndrome is dryness. The salivary glands are often attacked and slowly destroyed, leaving the mouth extremely dry and sticky. Swallowing and talking become difficult. Normally, the saliva washes the teeth clean. Saliva cannot perform this function in Sjögren's syndrome, so the teeth develop many cavities and decay quickly. The parotid glands produce the majority of the mouth's saliva. They are located lying over the jaw bones behind the area of the cheeks and in front of the ears, and may become significantly enlarged in Sjögren's syndrome.

The eyes also become extremely dry as the tear glands (called glands of lacrimation) are slowly destroyed. Eye symptoms include itching, burning, redness, increased sensitivity to light, and thick secretions gathering at the eye corners closest to the nose. The cornea may have small irritated pits in its surface (ulcerations).

Destruction of glands in other areas of the body may cause a variety of symptoms. In the nose, dryness may result in nosebleeds. In the rest of the respiratory tract, the rates of ear infection, hoarseness, bronchitis, and pneumonia may increase. Vaginal dryness can be quite uncomfortable. Rarely, the pancreas may slow production of enzymes important for digestion. The kidney may malfunction. About 33% of all patients with Sjögren's syndrome have other symptoms unrelated to gland destruction. These symptoms include fatigue, decreased energy, fevers, muscle aches and pains, and joint pain.

Many patients with SS also develop a variety of skin problems that include dry patches, vasculitis, and cutaneous B-cell lymphoma. These and other dermatologic disorders are more common in SS than was previously thought.

Patients who also have other autoimmune diseases will suffer from the symptoms specific to those conditions.

In addition to physical symptoms, patients with SS appear to be at increased risk for depression and other mood disorders.

Diagnosis

Diagnosis of Sjögren's syndrome is based on the patient having at least three consecutive months of bothersome eye and/or mouth dryness. A variety of tests can then be done to determine the quantity of tears produced, the quantity of saliva produced, and the presence or absence of antibodies that could be involved in the destruction of glands.

Treatment

There is no cure for Sjögren's syndrome. Instead, treatment usually attempts to reduce the discomfort and complications associated with dryness of the eyes and mouth (and other areas). Artificial tears are available, and may need to be used up to every 30 minutes. By using these types of products, the patient is more comfortable and avoids the complications associated with eyes that are overly dry. Dry mouth is treated by sipping fluids slowly but constantly throughout the day. Sugarless chewing gum can also be helpful. An artificial saliva is available for use as a mouthwash. Patients may also be given such drugs as pilocarpine (Salagen) or cevimeline (Evoxac) to increase saliva and tear secretions. Careful dental hygiene is important in order to avoid tooth decay, and it is wise for patients to decrease sugar intake. Vaginal dryness can be treated with certain gel preparations. Steroid medications may be required when other symptoms of autoimmune disorders complicate Sjögren's syndrome. However, these medications should be avoided when possible because they may make the cornea thin and even more susceptible to injury.

Key terms

Autoimmune disorder — A disorder in which the body's immune cells mistake the body's own tissues as foreign invaders; the immune cells then work to destroy tissues in the body.

Cornea — A transparent structure of the eye over the iris and pupil; light must pass through the cornea to make vision possible.

Coxsackievirus — Any of a group of enteroviruses that produce a disease in humans characterized by fever and rash. Coxsackieviruses are named for the town in upstate New York where they were first identified.

Immune system — The complex network of organs and blood cells that protect the body from foreign invaders, like bacteria, viruses, and fungi.

Prognosis

The prognosis for patients with primary Sjögren's syndrome is particularly good; these patients have a normal life expectancy. Although the condition is quite annoying, serious complications rarely occur. The prognosis for patients with secondary Sjögren's syndrome varies since it depends on the prognosis for the accompanying autoimmune disorder.

Prevention

Since the cause of Sjögren's syndrome is unknown as of 2004, there are no known ways to prevent this syndrome.

Resources

Books

Beers, Mark H., MD, and Robert Berkow, MD., editors. "Diffuse Connective Tissue Disease." Section 5, Chapter 50 In The Merck Manual of Diagnosis and Therapy. Whitehouse Station, NJ: Merck Research Laboratories, 2004.

Moutsopoulos, Haralampos M. "Sjögren's Syndrome." In Harrison's Principles of Internal Medicine, edited by Anthony S. Fauci, et al. New York: McGraw-Hill, 1997.

Periodicals

Bell, Mary, et al. "Sjögren's Syndrome: A Critical Review of Clinical Management." The Journal of Rheumatology 26, no. 9 (2001): 2051-2059.

Francis, Mark L., MD. "Sjogren Syndrome." eMedicine July 1, 2004. http://emedicine.com/med/topic2136.htm.

Ono, M., E. Takamura, K. Shinozaki, et al. "Therapeutic Effect of Cevimeline on Dry Eye in Patients with Sjögren's Syndrome: A Randomized, Double-Blind Clinical Study." American Journal of Ophthalmology 138 (July 2004): 6-17.

Roguedas, A. M., L. Misery, B. Sassolas, et al. "Cutaneous Manifestations of Primary Sjögren's Syndrome Are Underestimated." Clinical and Experimental Rheumatology 22 (September-October 2004): 632-636.

Stevenson, H. A., M. E. Jones, J. L. Rostron, et al. "UK Patients with Primary Sjögren's Syndrome Are at Increased Risk from Clinical Depression." Gerodontology 21 (September 2004): 141-145.

Triantafyllopoulou, A., N. Tapinos, and H. M. Moutsopoulos. "Evidence for Coxsackievirus Infection in Primary Sjögren's Syndrome." Arthritis and Rheumatism 50 (September 2004): 2897-2902.

Organizations

American College of Rheumatology. 1800 Century Place, Suite 250, Atlanta, GA 30345-4300. (404) 633-3777. Fax: (404) 633-1870. http://www.rheumatology.org.

Sjögren's Syndrome Foundation, Inc. 8120 Woodmont Avenue, Bethesda, MD 20814. (800) 475-6473. Fax: (301) 718-0322. http://www.sjogrens.org.

Other

American College of Rheumatology Fact Sheet. "Sjögren's Syndrome." http://www.rheumatology.org/public/factsheets/sjogrens_new.asp?aud=pat.

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Sjögren's syndrome

a symptom complex marked by keratoconjunctivitis sicca and xerostomia often occurring in association with other inflammatory disorders such as immune-mediated arthritis and systemic lupus erythematosus. Reported in dogs.