Sarcoidosis
Diagnosis
Preliminary diagnosis of sarcoidosis is based on the patient's
medical history, routine tests, a physical examination, and a chest
x-ray.
The doctor confirms the diagnosis of sarcoidosis by eliminating
other diseases with similar features. There include such
granulomatous diseases as berylliosis, tuberculosis, farmer's lung
disease (hypersensitivity pneumonitis), fungal infections,
rheumatoid arthritis, rheumatic fever, and cancer of the lymph nodes
(lymphoma).
Medical signs and symptoms
In addition to the lungs and lymph nodes, the body organs more
likely than others to be affected by sarcoidosis are the liver,
skin, heart, nervous system, and kidneys, in that order of
frequency. Rarely, any organ can be involved. Patients can have
symptoms related to the specific organ affected, they can have
general symptoms, or they can be without any symptoms. Symptoms can
vary according to how long the illness has been present, where the
granulomas are forming, how much tissue has been involved and
whether the granulomatous fibrotic process is active.
Even when there are no symptoms, a doctor can sometimes pick up
signs of sarcoidosis during a routine examination, usually a chest
x-ray. The patient's age and race or ethnic group can raise an
additional red flag that a sign or symptom of illness could be
related to sarcoidosis. Enlargement of the salivary or tear glands
and cysts in bone tissue are also possible signs of sarcoidosis.
LUNGS: The lungs are usually the first site involves in sarcoidosis.
Indeed, about 9 out of 10 sarcoidosis patients have some type of
lung of problem, with nearly one-third of these patients showing
some respiratory symptom usually coughing, either dry or with
phlegm, and dyspnea (shortness of breath). Occasionally, patients
have chest pain and a feeling of tightness in the chest. It is
thought that sarcoidosis of the lungs begins with alveolitis
(inflammation of the alveoli), the tiny sac like air spaces in the
lungs where carbon dioxide and oxygen are exchanged. Alveolitis
either clears up spontaneously or leads to granuloma formation.
Eventually fibrosis (scarring) can form, causing the lung to stiffen
and make breathing even more difficult.
EYES: Eye involvement occurs in about 20 to 30 percent of patients
with sarcoidosis, particularly in children who get the disease.
Almost any part of the eye can be affected the membranes of the
eyelids, cornea, outer coat of the eyeball (sclera), retina, and
lens. The eye involvement can start with no symptoms at all or with
reddening or watery eyes. In a few cases, cataracts, glaucoma, and
blindness can result. Every patient with sarcoidosis should be
evaluated by an eye physician (ophthalmologist) at least annually.
SKIN: The skin is affected in about 20 percent of sarcoidosis
patients. Skin sarcoidosis is usually marked by small, raised
patches on the face. Occasionally the patches are purplish in color
and larger. Patches can also appear on limbs, face, and buttocks.
Other symptoms include erythema nodosum (red bumps), mostly on the
legs and often accompanied by arthritis in the ankles, elbows,
wrists, and hands. Erythema nodosum usually goes away, but other
skin problems can persist.
NERVOUS SYSTEM: In an occasional case (1 to 5 percent), sarcoidosis
can lead to neurological problems. For example, sarcoid granulomas
can appear the brain, spinal cord, and facial and optic nerves.
Facial paralysis and other symptoms of nerve damage call for prompt
treatment.
Chest Film (CXRAY) stages of Sarcoidosis
The term stages can be misleading in that patients do not always
progress from a mild case to a more serious case. Stage I does not
always progress to stage two, three etc. They do not imply a
progression, rather these are patterns seen on chest films. In fact,
because these stages were originally defined from chest films, there
may not be any significant difference in symptoms, pulmonary
function tests or prognosis between Stage I and II. In many cases
the disease remits and never returns, regardless of whether in Stage
I or II. Generally, most patients with Stage III or IV do have worse
disease, symptoms and prognosis but often their chest film
overestimates their symptoms.
STAGE I:
• Thoracic (hilar and mediastinal) lymphadenopathy
• Normal lung parenchyma
• Enlarged lymph nodes (glands) in the middle of the
chest
These nodes sit outside of the lung. When sarcoidosis affects these
or other nodes in the body, they increase in size and become visible
on chest film and chest CAT scan. Biopsy of these nodes by
mediastinoscopy (scope placed into to the middle of the chest
through an incision. This procedure requires general anesthesia)) is
one way of defining the diagnosis. Other diseases that can cause
these findings are tuberculosis, fungal disease, lymphoma, lung
cancer, etc.
STAGE II:
• Thoracic (hilar and mediastinal) lymphadenopathy
• Abnormal lung parenchyma
• Enlarged lymph nodes/glands in the middle part of
the chest with abnormal lungs on chest x-ray films
as well
This disease is more extensive than Stage I, because now there is
radiographic evidence of lung involvement instead of just node
involvement. However, this may be misleading. Most patients, 75 to
95% of those with only Stage I by chest film, have lung involvement
on biopsy of the lung. Biopsy of the lung is normally done by
bronchoscopy (scope placed down the mouth into the lung. This
procedure does not require general anesthesia) Symptoms and
Pulmonary function tests may or may not be different between Stage I
and II. These findings would suggest that in many patients there is
no or minimal difference between Stage I and II.
STAGE III:
• Abnormal lung parenchyma
• No lymphadenopathy
• Abnormal lungs on chest film images but no enlarged
lymph nodes/glands in the middle part of the chest
Suggests a later stage of progression and more severe disease
(symptoms and pulmonary function tests).
STAGE IV:
• Permanent lung fibrosis
• Destruction of the lung with damage to upper lobes and scar tissue
formation (irreversible lung disease)
Labrotory tests
No single test can be relied on for a correct diagnosis of
sarcoidosis. X-rays and blood tests are usually the first procedures
the doctor will order. Pulmonary function tests often provide clues
to diagnosis/but are more useful for determining the severity of
lung involvement. Other tests may also be used, some more often than
others.
CHEST X-RAY: A picture of the lungs, heart, as well as the
surrounding tissues containing lymph nodes, where infection-fighting
white blood cells form, can give the first indication of sarcoidosis.
For example, a swelling of the lymph glands between the two lungs
can show up on an x-ray. An x-ray can also show which areas of the
lung are affected. Chest x-ray can be classified as Stage I, II, III
or IV as described above.
PULMONARY FUNCTION TESTS: Breathing tests called pulmonary function
tests (PFT), evaluate how well the lungs are doing their job of
expanding and exchanging oxygen and carbon dioxide with the blood.
Granulomas and fibrosis of lung tissue may decrease lung capacity
and disturb the normal flow of gases between the lungs and the
blood. Important PFTs include spirometry (flow rate), lung volumes
and diffusion. Occasionally, PFTs during or post-exercise may also
be helpful in characterizing the extent and severity of the disease
process.
BLOOD TESTS: Blood analyses can evaluate the number and types of
blood cells in the body and how well the cells are functioning. They
can also measure the levels of various blood proteins known to be
involved in immunological activities, and they can show increases in
serum calcium levels and abnormal liver function that can accompany
sarcoidosis.
Blood tests can measure a blood substance called angiotensin-converting
enzyme (ACE). Because the cells that make up granulomas secrete
large amounts of ACE, the enzyme levels may be high in patients with
sarcoidosis. ACE levels, however, are not always high in sarcoidosis
patients, and increased ACE levels can also show up in other
illnesses.
BRONCHOALVEOLAR LAVAGE: This tests uses an instrument called a
bronchoscope a long, narrow tube with a light at the end to wash
out, or lavage, cells and other materials from inside the lungs.
This wash fluid is then examined for the amount of various cells and
other substances that reflect inflammation and immune activity in
the lungs. A high number of white blood cells in this fluid usually
indicate an inflammation in the lungs.
BIOSPY: Microscopic examination of tissue specimens can tell a
doctor that granulomas typical of sarcoidosis have formed in your
body. Specimens of lung tissue are obtained with a bronchoscope, or
less often by open chest surgery or a video assisted thorascope
(VAT). Biopsies of chest lymph nodes are obtained with a
mediastinoscope or less often by open chest surgery or a video
assisted thorascope (VAT). Occasionally, tissue specimens are
obtained from the eye, skin, or other lymph nodes when involvement
of those tissues is suspected. Rarely, sarcoidosis is found in
biopsy material of other organs taken for other purposes.
Examination of tissue provides a definitive diagnosis.
GALLIUM SCANNING: In this procedure, the doctor injects the
radioactive chemical element gallium-67 into the patient's vein. The
gallium collects at places in body affected by sarcoidosis and other
inflammatory conditions. Two days after the injection, the body is
scanned for radioactivity. Increase in gallium uptake at any site in
the body indicate that inflammatory activity has developed at the
site and also give an idea of which tissue, and how much tissue, has
been affected. However, since any type of inflammation causes
gallium uptake, a positive gallium scan does not necessarily mean
that the patient has sarcoidosis.
KVEIM TEST: This test involves injecting a standardized preparation
of sarcoid tissue material into the skin. Biopsy of the lump formed
at the point of injection is considered evidence for sarcoidosis. On
the other hand, the test result is not always positive in patients
with sarcoidosis. The Kveim test is not used often in the United
States because no test material has been approved for sale by U.S.
Food and Drug Administration. However, a few hospitals and clinics
may have some standardized test preparation prepared privately for
their own use
SLIT-LAMP EXAMINATION: An instrument called a slit lamp, with
permits examination of the inside of the eye, can be used to detect
silent damage from sarcoidosis.
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