Sarcoidosis (cont.)
How is sarcoidosis diagnosed?
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. These include such
granulomatous diseases as berylliosis (a disease
resulting from exposure to beryllium metal), tuberculosis, farmer's lung disease (hypersensitivity pneumonitis), fungal infections, rheumatoid arthritis, rheumatic fever, and cancer
of the lymph nodes (lymphoma).
What are some signs and symptoms that suggest possible sarcoidosis?
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. Patients can
have symptoms related to the specific organ affected, they can have only general
symptoms, or they can be without any symptoms whatsoever. Symptoms also can vary
according to how long the illness has been under way, where the granulomas are
forming, how much tissue has become affected, and whether the granulomatous
process is still active.
Even when there are no symptoms, a doctor can sometimes
detect signs of sarcoidosis during a routine examination, usually a chest x-
ray, or when checking out another complaint. 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 among sarcoidosis signals.
The lungs are usually the first site involved in
sarcoidosis. Indeed, about nine out of 10 sarcoidosis patients have some type of
lung problem, with nearly one-third of these patients showing some respiratory
symptoms—usually coughing, either dry or with phlegm, and
dyspnea. Occasionally, patients have chest pain and a feeling of tightness in the chest.
It is thought that sarcoidosis of the lungs begins with
inflammation of the alveoli (alveolitis), 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 can form, causing the lung to stiffen
and making breathing even more difficult.
Eye disease occurs in about 20%-30% 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.
The skin is affected in about 20% 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, 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.
Occasionally (1%-5%), sarcoidosis can lead to
nervous system problems. For example, sarcoid granulomas can appear in the
brain, spinal cord, and facial and optic nerves. Facial
paralysis and other symptoms of nerve damage call for prompt treatment with medications such as high doses of cortisone (see below). Also, people with sarcoidosis can have depression that is unrelated to the activity of the disease and is felt to be, in part, because of a misdirected immune system.
Symptoms can appear suddenly and then disappear. Sometimes,
however, they can continue over a lifetime.
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