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Introduction: You probably
know someone who has SS; the problem is that they probably
don�t know they have it. SS is a common yet
under-diagnosed condition causing dryness of the mouth and
eyes as well as inflammation in other parts of the body. This
condition seems to result from the body�s immune system
attacking the glands that make saliva and tears, causing these
glands to swell and/or malfunction.
SS affects
about 1% of the general population, which is about as common
as rheumatoid arthritis (RA) and 10 times as common as
systemic lupus erythematosus (SLE). Even though SS is common,
it is not commonly recognized. By the time a patient is
diagnosed with SS, an average of 9-11 years has elapsed since
the onset of symptoms. This delay is likely due to a
combination of factors, including patients blaming their
dryness on other factors (medications, allergies, other
illnesses, getting older, etc.) and lack of physician
awareness of SS.
Roughly 1/2 of patients with this disease have Primary
SS, and the remainder has Secondary SS, which is seen
along with another rheumatic disease such as RA or SLE. The
most common age of onset is between 40 and 60 years of age.
As with SLE, women with this condition outnumber men by about
9:1. While an aggravating disease, having SS does not
increase one�s mortality rate overall, and SS patients can
expect normal survival.
Features of SS: The key symptoms of
SS are due to an impaired ability to make adequate saliva
and/or tears. Loss of saliva and subsequent dry mouth may
result in difficulty chewing or swallowing food, loss of
taste, or accelerated tooth decay. Many individuals note that
they cannot eat crackers or other dry foods without water or
other liquid to wash it down, and those with SS often find the
need to keep a glass of water by their bedside to ease dry
mouth symptoms that awaken them from sleep at night. A burning
sensation in the mouth may also occur, which may be a sign of
yeast infection, a problem SS patients are prone to
developing.
Loss of tears
and dryness in the eyes may result in the eyes feeling gritty
or painful on the surface and those with SS often have the
feeling that something is in their eye. These symptoms are
often referred to as keratoconjunctivitis sicca (ker`a-to-kon-jungk`ti-vi`tis
sik`a). In severe cases, the cornea (surface of the eye) may
develop abrasions or ulcers. This complication makes SS
patients susceptible to viral or bacterial infections on the
surface of the eye.
In some individuals, the salivary glands may swell and become
uncomfortable. The most common glands that may be noticeably
swollen are the parotid (pa-rot`id) glands located on
the sides of the cheeks. Other glands less commonly involved
are located under the jaw. Infections (such as mumps) and
salivary gland stones can cause a similar type of swelling in
these glands, but SS can usually be distinguished by the
symptoms of dryness in the mouth.
SS may affect many other parts of the body as well. About 1/2
of those with SS have arthritis or at least joint and muscle
pain, and nearly 1/2 have hearing loss. Thyroid disease, nerve
damage, and irritation of the trachea (windpipe) are also
common problems in SS. Other organs occasionally involved
include the lungs, liver, brain, bladder, and kidneys. These
different parts of the body can become inflamed due to an
attack from the immune system much like what we see in
patients with SLE (see Systemic Lupus Erythematosus
section).
Another problem worth mentioning in SS is the increased risk
for developing lymphoma, a cancer of the lymph nodes and blood
cells. This occurs in 5% of SS patients, making them 44 times
more likely than the general population to develop lymphoma.
When this complication occurs, it is seen an average of 7.5
years after the diagnosis of SS is made. The development of
lymphoma is the exception to the rule that no excess mortality
is seen in SS. For this reason, any enlarged lymph node that
remains swollen for more that 4 weeks should be biopsied.
Diagnosis:
When a patient has symptoms of dry mouth and/or eyes, the next
step in deciding whether these symptoms represent SS is to
document either the presence of antibodies typical for SS,
loss of function of salivary or tear glands, or inflammation
of these glands. It is also important to exclude other causes
of these symptoms include medications (anti-histamines,
certain kinds of anti-depressants), radiation to the head and
neck, viral infections, diabetes, and a number of other
chronic illnesses.
A
physical examination may give certain clues to the diagnosis
of SS. About 1/3 of patients will have swollen salivary
glands, and many have a lack of normal �pooling� of the saliva
under the tongue. In some, the tongue is so dry that it has
the appearance of �crocodile skin.� The eyes may appear
irritated or red and may show a visible loss of moisture on
the surface. Two quick tests that can be done in a few
minutes in the office to provide further evidence for SS are
the Schirmer�s test and the Rose-Bengal test.
The Schirmer�s test involves inserting a strip of paper on
each lower eyelid and measuring the tear flow. The
Rose-Bengal test consists of a dye that is applied to the
surface of the eye to pick up small abrasions of the cornea
that are typical for SS. Any of these findings add more
evidence to support a SS diagnosis.
Studies of the salivary glands include x-ray studies and
salivary gland biopsy. The salivary glands can be imaged with
a study known as sialography, which involves injecting
dye into the gland through an opening in the cheek and
observing inflammation of the ducts in within the gland.
Ultrasound, nuclear medicine scans, and magnetic resonance
imaging (MRI) have also been used to visualize changes in the
glands suggestive of SS. The most specific and accurate study
of the salivary glands, however, is a salivary gland biopsy.
Most commonly, a small incision is made on the inner lower
lip, where small, pea-sized salivary glands are located, and
several glands are removed and examined under the microscope
for inflammation. This procedure is about 85% accurate in
diagnosing SS. While not every patient may need this biopsy
to confirm the diagnosis, it is very useful in cases where
other evidence has been unclear.
Antibodies seen in SS include the anti-nuclear antibody
(ANA) also seen in SLE, the rheumatoid factor (RF) also
observed in RA, and some more specific antibodies known as
Ro/SSA and La/SSB. While these latter two markers
can also be seen in some SLE patients, their presence in a
patient who has dry mouth and/or eyes in the absence of other
features of SLE strongly supports a diagnosis of SS. On the
average, about 70% of SS demonstrate these antibodies; their
absence, therefore, does not rule out the diagnosis. In fact,
some patients will exhibit none of these antibodies.
In these individuals, a salivary gland biopsy or other studies
may be most useful if a diagnosis of SS is to be pursued.
While SS may be a difficult illness to evaluate, a combination
of these evaluations in the hands of an experienced physician
can help determine whether an individual has SS versus a
number of other illnesses that can demonstrate the same
symptoms. To make matters more complicated, many patients who
have SS also have another rheumatic disease such as SLE or RA,
and these conditions should sought in any patient with
symptoms suggesting SS.
Therapy:
Treatment of SS consists of measures that
are aimed at relieving dry mouth and eye symptoms as well as
medications that suppress the inflammation causing the
problems in the glands and other parts of the body. In
general, the severity of the symptoms, the type of symptoms
present, and the extent in the disease in the rest of the body
determines what therapy is most appropriate in an individual
patient.
Dry mouth symptoms can be treated an approach as simple as
extra sips of water. Small, frequent sips rather than large
volumes seem to be adequate to relieve symptoms. Over the
counter gels and other preparations (Xerolube, Salivart,
Oral Balance Gel, Mouth Kote, etc.) are available over the
counter and can add moisture to a dry mouth when water isn�t
enough. Close attention to good dental care is crucial to
prevent cavities. Extra fluoride may be helpful, and if gum
is to be chewed, it should be sugar-free to avoid the risk of
tooth decay associated with extra sugar. Yeast infections in
the mouth also need to be treated when a patient demonstrates
a painful or burning sensation in the mouth.
Dry eye symptoms may be treated initially with a variety of
over the counter artificial tear preparations or gels (Cellufresh,
Refresh Plus, Celluvisc, Lacrilube, etc.). Humidifiers in
the home, especially in the bedroom at night, can also help
reduce a sensation of dry eyes, and fans should be avoided, as
they can further dry the eyes.
Punctal occlusion can
add moisture to the eyes in difficult cases. This procedure
is typically performed by an eye doctor and involves inserting
temporary plugs in the puncta, two tiny opening located
on the lower inner eyelids that drain the tears. If the
temporary plugs provide relief of symptoms, the puncta can be
permanently sealed off with a laser.
A
review of a patient�s list of medications should be reviewed,
and any non-essential drugs should be discontinued only
after a discussion with the prescribing physician. This
simple measure may do away with the need for other
therapies.
Medications focusing on improving flow of saliva and/or tears
include pilocarpine (Salagen) and cevimeline (Evoxac).
These medications both work mostly on the salivary glands and
stimulate flow of saliva, and to a lesser extent tears. Both
medications must be used consistently for several months
before any benefit is seen but may be quite useful at
relieving symptoms. Other than excessive sweating, side
effects are uncommon and usually mild.
Suppressing the inflammation of SS is an additional
challenge. For those with arthritis, salivary gland swelling,
and fatigue, hydroxychloroquine (Plaquenil) may be
beneficial. This drug is also used for treating mild SLE and
RA and has few major side effects, the major complication
being a 1 in 1,000 risk of changes in the retina (the back
part of the eye) that can be identified by monitoring every 6
to 12 months with an eye doctor. For certain patients, drugs
that more powerfully suppress the immune system such as
methotrexate or cyclophosphamide may be needed.
Because of the side effects of these medications and the need
for frequent monitoring, they should be reserved for resistant
disease or complications involving other organs (see
Medications section or sections on RA or SLE).
Eye drops containing cyclosporine (Restasis) have
recently been developed for treating dry eyes in SS and have
the advantage of directly suppressing the inflammation in the
tear glands as well as on the surface of the cornea. These
drops must be administered consistently twice a day for
several months if they are to be effective but can produce
dramatic results if taken correctly. Another method for
treating the inflammation in the salivary glands directly are
lozenges containing interferon, a substance produced in
the body known to have effects on inflammation. While not
expected to be available for a few years, preliminary studies
look quite promising.
Only by being aware of SS can this disease be identified and
only by being identified can this disease be treated and
complications be prevented. Hopefully, the future will hold
yet more therapies to reduce debilitating symptoms and
potential damage that can result from SS. |
