What is Sarcoidosis?
Posted on October 20, 2011 by Jeffrey
Sarcoidosis is a disease that causes inflammation of the body’s tissues. It affects multiple systems and is characterized by the
formation of granulomas (small lumps) that can be either inside
the body or on the body’s exterior. Sarcoidosis predominantly
affects the lung and the lymphatic system, but virtually any
organ can be involved.
In sarcoidosis, immune system cells that cause inflammation overreact
and cluster together to form tiny lumps called granulomas. If too
many of these granulomas form in one organ, it may not be able to
work correctly. For example, if the granulomas damage healthy tissue
in the lungs, scarring and stiffness may occur and limit how much air
the lungs can hold. This condition is known as pulmonary fibrosis. The
problems caused by sarcoidosis differ depending on which organ is
Who Has It
It is found throughout the world, among almost all races and ages and
in both sexes. However, it is most common among African Americans
and northern European Whites. People of Scandinavian, German, Irish,
Asian and Puerto Rican origin also are more prone to sarcoidosis than
the general population.
Prevalence rates for sarcoidosis can only be estimated because it can
easily escape diagnosis. Prevalence estimates in the United States range
from less than 1 to 40 cases per 100,000 population. Sarcoidosis can
affect people of all ages, but it occurs most commonly in adults from 20
to 40 years of age. Newer research suggests that there is a second peak
in sarcoidosis, especially among women, over the age of 50.
Although uncommon, death from sarcoidosis can occur if the disease
causes serious damage to a vital organ. The most common cause of
mortality associated with sarcoidosis is pulmonary fibrosis resulting
from the disease. In the United States, there were 924 deaths due to
sarcoidosis in 2006, an age-adjusted death rate of 0.32 per 100,000. Both
of these numbers are higher than the average number of deaths (about
821 per year) and the age-adjusted death rate (0.30 per 100,000) for
1999 through 2006.
The cause of sarcoidosis is not yet known. Most researchers agree
that sarcoidosis involves an altered immune system but they
do not know the source of the problem or what triggers such a response. Some researchers believe that sarcoidosis results from a
respiratory infection caused by a virus, bacteria, or an unidentified
environmental toxin. There is also some evidence of a genetic
basis for sarcoidosis. Current theories are that sarcoidosis develops
from an interaction between a preexisting genetic risk for it and a
triggering event, such as an infection or environmental exposure.
More research is needed to determine the exact cause for this
In more than 90 percent of cases, sarcoidosis affects the lungs.
Respiratory symptoms are present in one-third to half of cases, such
as shortness of breath, dry cough, and chest pain.10 Other common
symptoms include fatigue, lymph node swelling or soreness, weight
loss, and reddened, watery, or sore eyes. In some cases, symptoms can
also appear outside of the lungs, such as lumps, ulcers, discolored skin
or skin sores on the back, arms, legs, scalp and face.
Diagnosing sarcoidosis is a process of elimination. Many other
respiratory diseases must be ruled out first. X-rays and other scans
are often used to check the lungs and other organs for granulomas. A
sample of tissue from the affected area (biopsy) is usually required to
confirm the disease. When the lungs are involved, a bronchoscopy is
used to acquire the tissue sample. In this procedure, a long, thin tube is
inserted through the nose or mouth and down the throat to the lungs.12
Treatment for sarcoidosis varies for each individual patient. In over
half of the cases, sarcoidosis only lasts for 12 to 36 months.13 In cases
that do not involve certain organs or that have no additional problems
from the disease, treatment is not always necessary.14 However, 10 to 20
percent of sarcoidosis patients are left with permanent effects from the
disease. Among those whose lungs are impacted, 20 to 30 percent end
up with permanent lung damage.
For a small percentage of patients, their sarcoidosis can become
chronic, lasting for many years. For those patients, therapy primarily
targets ways to keep the lungs and any other affected organs
working and to relieve the symptoms. Steroids are commonly
prescribed to reduce inflammation. Frequent check-ups are also
important so that doctors can monitor the illness and if necessary,
Most people with sarcoidosis can lead normal lives. Patients need
to follow instructions from their physician and take all medication
diligently. It is also particularly important that sarcoidosis patients do
not smoke, and avoid exposure to dust and chemicals that can harm