What Is Sarcoidosis?
Sarcoidosis (sar-koy-DO-sis) is a disease of unknown
cause that leads to inflammation. It can affect various organs in the body.
Normally, your immune system defends your body
against foreign or harmful substances. For example, it sends special cells to
protect organs that are in danger.
These cells release chemicals that recruit other
cells to isolate and destroy the harmful substance. Inflammation occurs during
this process. Once the harmful substance is destroyed, the cells and the
inflammation go away.
In people who have sarcoidosis, the inflammation
doesn't go away. Instead, some of the immune system cells cluster to form lumps
called granulomas (gran-yu-LO-mas) in various organs in your body.
Overview
Sarcoidosis can affect any organ in your body.
However, it's more likely to occur in some organs than in others. The disease
usually starts in the lungs, skin, and/or lymph nodes (especially the lymph
nodes in your chest).
The disease also often affects the eyes and the
liver. Although less common, sarcoidosis can affect the heart and brain,
leading to serious complications.
If many granulomas form in an organ, they can affect
how the organ works. This can cause signs and symptoms. Signs and symptoms vary
depending on which organs are affected. Many people who have sarcoidosis have
no symptoms or mild symptoms.
Lofgren's syndrome is a classic set of signs and
symptoms that is typical in some people who have sarcoidosis. Lofgren's
syndrome may cause fever, enlarged lymph nodes, arthritis (usually in the
ankles), and/or erythema nodosum (er-i-THE-ma no-DO-sum).
Erythema nodosum is a rash of red or reddish-purple
bumps on your ankles and shins. The rash may be warm and tender to the
touch.
Treatment for sarcoidosis also varies depending on
which organs are affected. Your doctor may prescribe topical treatments and/or
medicines to treat the disease. Not everyone who has sarcoidosis needs
treatment.
Outlook
The outcome of sarcoidosis varies. Many people
recover from the disease with few or no long-term problems.
More than half of the people who have sarcoidosis
have remission within 3 years of diagnosis. "Remission" means the disease isn't
active, but it can return.
Two-thirds of people who have the disease have
remission within 10 years of diagnosis. People who have Lofgren's syndrome
usually have remission. Relapse (return of the disease) 1 or more years after
remission occurs in less than 5 percent of patients.
Sarcoidosis leads to organ damage in about one-third
of the people diagnosed with the disease. Damage may occur over many years and
involve more than one organ. Rarely, sarcoidosis can be fatal. Death usually is
the result of complications with the lungs, heart, or brain.
Poor outcomes are more likely in people who have
advanced disease and show little improvement from treatment.
Certain people are at higher risk for poor outcomes
from chronic (long-term) sarcoidosis. This includes people who have lung
scarring, heart or brain complications, or lupus pernio (LU-pus PAR-ne-o).
Lupus pernio is a serious skin condition that sarcoidosis may cause.
Research is ongoing for new and better treatments
for sarcoidosis.
February 2009
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