What is Sarcoidosis? Sarcoidosis
(pronounced SAR-COY-DOE-SIS) is an
inflammatory disease that can affect almost any organ in the
body. It causes heightened immunity, which means that a
person’s immune system, which normally protects the body
from infection and disease, overreacts, resulting in damage
to the body’s own tissues. The classic feature of
sarcoidosis is the formation of granulomas, microscopic
clumps of inflammatory cells that group together (and look
like granules, hence the name). When too many of these
clumps form in an organ they can interfere with how that
organ functions.
In people in the United States, sarcoidosis most commonly
targets the lungs and lymph nodes, but the disease can and
usually does affect others organs, too, including (but not
limited to) the skin, eyes, liver, salivary glands, sinuses,
kidneys, heart, the muscles and bones, and the brain and
nervous system.
What Causes Sarcoidosis?
No one knows exactly what causes sarcoidosis, but it is
probably due to a combination of factors. Some research
suggests that bacteria, viruses or chemicals might trigger
the disease. Although such triggers might not bother most
people, it is possible that in someone with the right
genetic predisposition they provoke the immune system to
develop the inflammation associated with sarcoidosis.
The fact that a person is more likely to develop the disease
if someone in his or her close family has the disease
strongly suggests that genetics plays a role. Researchers
have not discovered the genes for sarcoidosis yet, but it
seems likely that more than one gene is involved.
Who Has Sarcoidosis?
Once thought rare, sarcoidosis is now known to be common and
affects people worldwide. The disease can affect people of
any age, race and gender.
However, it is most common among adults between the
ages of 20 and 40 and in certain ethnic groups.
-
In the
United States, it is most common in African Americans
and people of European – particularly Scandinavian –
descent.
-
Among
African Americans, the most affected U.S. group, the
estimated lifetime risk of developing sarcoidosis might
be as high as 2 percent.
-
Most
studies suggest a higher disease rate for women.
Disease
severity can vary by race or ethnicity.
-
In the United States, sarcoidosis
frequently occurs more often and more severely among
African Americans than among Caucasians.
-
Appearance of the disease outside of the lung is common
in certain populations, for example: the eyes (chronic
uveitis) in African Americans, painful skin lumps in
Northern Europeans and the heart and eyes in Japanese.
What are
the Symptoms?
Sarcoidosis is a multi-system disorder. Symptoms
typically depend on which organ the disease affects.
Most often the disease will affect the lungs.
-
General:
About one third of patients will experience non-specific
symptoms of fever, fatigue, weight loss, night sweats
and an overall feeling of malaise (or ill health).
-
Lungs:
The lungs are affected in more than 90% of patients with
sarcoidosis. A cough that does not go away, shortness
of breath, particularly with exertion and chest pain
occur most frequently with the pulmonary form of the
disease.
-
Lymph Nodes:
Up to 90% of sarcoidosis patients have enlarged lymph
nodes. Most often they are in the neck, but those under
the chin, in the arm pits and in the groin can be
affected. The spleen,
which is part of the lymphatic system, can also be
affected.
-
Liver:
Although between 50% to 80% of patients with sarcoidosis
will have granulomas in their liver, most are without
symptoms and do not require treatment.
-
Heart:
: Researchers estimate that cardiac sarcoidosis, affects
more than 10 percent of people with sarcoidosis in the
United States, and perhaps as many as 25 percent. Sarcoidosis can cause the heart to beat weakly
resulting in shortness of breath and swelling in the
legs. It can also cause palpitations (irregular
heartbeat).
-
Brain & Nervous System:
From 5% to 13% of patients have neurologic disease.
Symptoms can include headaches, visual problems,
weakness or numbness of an arm or leg and facial palsy.
-
Skin:
One in four (25%) of patients will have skin
involvement. Painful or red, raised bumps on
the legs or arms (called erythema nodosum), discoloration of the
nose, cheeks, lips and ears (called lupus pernio) or
small brownish and painless skin patches are symptoms of
the cutaneous form of the disease.
-
Bones, Joints & Muscles:
Joint pain occurs in about one-third of patients. Other symptoms
include a mass in the muscle, muscle weakness and
arthritis in the joints of the ankles, knees, elbows,
wrists, hands and feet.
-
Eyes:
Any part of the eye can be affected by sarcoidosis and
about 25% of patients have ocular involvement. Common
symptoms include: burning, itching, tearing, pain, red
eye, sensitivity to light (photophobia), dryness, seeing
black spots (called floaters) and blurred vision.
Chronic uveitis (inflammation of the membranes or uvea
of the eye) can lead to glaucoma, cataracts and
blindness.
-
Sinuses, Nasal Muscosa
(lining) & Larynx:
About 5% of patients will have involvement in the
sinuses with symptoms that can include sinusitis,
hoarseness or shortness of breath.
-
Other Organs:
Rarely, the gastrointestinal tract, reproductive organs,
salivary glands and the kidneys are affected.
How is Sarcoidosis Diagnosed? Symptoms of
sarcoidosis can mimic those of other diseases. In some
cases sarcoidosis may be diagnosed by excluding these other
similar diseases. Frequently, sarcoidosis is diagnosed
because a routine chest x-ray shows an abnormality. To
accurately diagnose the disease, most doctors will take a
medical history and perform a physical examination.
Laboratory tests of the blood, chest x-rays, breathing tests
and biopsy are all diagnostic tools.
What is the Treatment for Sarcoidosis?
Different treatments will work better for different people,
and sometimes more than one drug is used. In some cases, no
treatment is needed. But, for some patients, intense
treatment is required, especially if organs like the lungs,
eyes, heart or central nervous system are affected.
Treatment is generally done to control symptoms or to
improve the function of organs affected by the disease.
While
progress has been made in understanding the symptoms and
better diagnosing the disease, little is known about who is
susceptible to sarcoidosis and the cause remains unknown.
With increased research, discovering the cause, improving
treatment and finding a cure may be well within our reach.
You can make a difference by
donating to FSR. Learn More. |