Sarcoidosis: Causes, Symptoms & Treatment

Sarcoidosis is an inflammatory disease that affects one or more organs but most commonly affects the lungs and lymph glands. As a result of the inflammation, abnormal lumps or nodules (called granulomas) form in one or more organs of the body. These granulomas may change the normal structure and possibly the function of the affected organ(s).

Sarcoidosis

How does the condition progress?

Although no one can predict how sarcoidosis will progress in an individual patient, some clues as to disease course can be gained from patient symptoms, findings from physical and laboratory studies, and patient race. For example, a sudden onset of general symptoms--such as weight loss, fatigue, fever, or just an overall feeling of ill health--usually means that the course of sarcoidosis will be relatively short and mild in severity. Symptoms of shortness of breath and some types of skin involvement mean that sarcoidosis will be more long-lasting and severe.

In Caucasians, the disease often appears suddenly, which usually indicates a more mild form of the disease that is of short duration. African-Americans and Puerto Ricans, on the other hand, tend to develop the more long-term and severe form of the disease.

In the United States, the lungs are often the most common site of initial symptoms for those who experience a gradual onset of their long-term disease. Lung symptoms are common in African-Americans, Puerto Ricans, and Scandinavians. Persistent dry cough, fatigue, and shortness of breath are the most common initial lung-related complaints.

What systems of the body are affected by sarcoidosis?

Beyond the lungs and lymph glands, the body organs or systems affected by sarcoidosis that are associated with the most noticeable symptoms are the skin, eyes, musculoskeletal system, nervous system, heart, liver, and kidneys, in this order. Patients can have symptoms related to the specific organ affected, or can have general symptoms, or can have no symptoms whatsoever (for example, laboratory findings frequently show the liver to be affected by sarcoidosis, yet patients generally do not report any liver-related symptoms).
An individual patient's symptoms can also vary according to how long the illness has been under way, where granulomas are forming, how much tissue has become affected, and whether granuloma formation is still active or has developed into scar.

Some patients who experience sudden onset of disease have Lofgren’s syndrome, a form of sarcoidosis that affects the lymph nodes and is accompanied by a skin condition that produces red nodules under the skin, as well as fever and arthritis pain. Patients with Lofgren’s syndrome usually can expect a good outcome; the disease goes away on its own in 85% to 90% of people.

How sarcoidosis progresses: What happens at the tissue level

At the tissue or cellular level, sarcoidosis disease progression can be divided into three phases:

• The first change that is seen is inflammation.
• In the second phase, granulomas form. Granulomas are masses or nodules of chronically inflamed tissue and are the classic sign of sarcoidosis Granulomas are the body’s attempt to wall off or isolate organisms and other foreign particles that are difficult for the immune system to eradicate or dispose of.
• In the third phase, fibrosis (scarring) of tissues or organs occurs. If scarring is extensive in a vital organ, sarcoidosis is sometimes fatal.

In some people, the disease advances from one phase to the next in the tissues of the organ affected. In others, the different phases of tissue changes take place within the same organ at the same time. In many patients with sarcoidosis, the granulomas go away on their own in 2 to 3 years without the patient knowing or doing anything about them. In others, the granulomas progress to irreversible fibrosis. The immune system changes that allow one person’s disease to progress while another person’s disease resolves are not well understood and continue to be investigated.

Does sarcoidosis run in families?

While the latest research does appear to indicate a genetic susceptibility to the disease, more research is needed to clearly identify and confirm the genes involved. However, numerous reports have revealed racial/ethnic and family-line occurrences, including the following:

• Irish immigrants in London have a three-fold likelihood of developing sarcoidosis compared with native Londoners.
• Natives of Martinique living in France have an eight-fold higher chance of developing the disease compared with the native French population.
• African-Americans face a 4 to 17 times greater risk of the disease compared with Caucasians.
• Within individual families, the presence of the disease in a first- or second-degree relative increases the risk by nearly five-fold.

Still other types of disease clusters have been identified, including seasonal and occupational clustering. Researchers in Greece, Spain, and Japan have reported a clustering of diagnoses of sarcoidosis in the months of March to May, April to June, and June to July. In the United States, a higher percentage of cases of sarcoidosis have been reported in health care workers, naval aircraft servicemen, and firefighters.

What are symptoms of sarcoidosis when it affects the lungs?

The lungs are affected in more than 90% of individuals with sarcoidosis. Even in individuals whose disease primarily affects other organs, the lungs are usually affected as well. Shortness of breath, cough, and chest discomfort are the most common lung-related symptoms. Patients may be free of chest symptoms despite an abnormal chest x-ray and biopsy-proven sarcoidosis. Occasionally, patients have chest pain – which is usually described as a vague tightness of the chest – but sometimes the pain can be severe and similar to cardiac pain.

It's thought that sarcoidosis of the lungs begins with alveolitis. Alveolitis is inflammation of the alveoli, which are the tiny sac-like air spaces in the lungs where carbon dioxide and oxygen are exchanged. Alveolitis either clears up by itself or progresses to granuloma formation. Samples of lung tissue may show the presence of granulomas.

Granulomas in the lungs can lead to narrowing of the airways, enlargement of lymph nodes in the chest, and inflammation and scarring (fibrosis) of lung tissue. The scarring causes the lung tissue to stiffen and destroys the air sacs, making it more difficult to breathe.

What are symptoms of sarcoidosis when it affects the skin?

About 25% of patients with sarcoidosis develop at least one skin symptom. Tender, painful, reddish bumps or patches on the skin (erythema nodosum) – usually on the shins – accompanied by swollen and painful joints are common. Lupus pernio (a chronic skin condition marked by purple-colored lesions on the cheeks, lips, nose, and ears) is common in older African-Americans and West Indian women with long-standing disease.

Other skin signs in patients with long-term disease include plaques, patches (with and without color), nodules, and hair loss. The range in appearance of skin-related lesions – from subtle, painless rashes to deep scars – often correlates with the severity of sarcoidosis involving the internal organs. The skin changes can be visible or under the skin.

What are symptoms of sarcoidosis when it affects the eyes?

About 25% of people with sarcoidosis have eye symptoms. Inflammation of almost any part of the eye can occur--this includes the membranes of the eyelids, cornea, outer coat of the eyeball (sclera), iris, retina, and lens. The most common eye-related symptom is acute anterior uveitis (inflammation of a layer of the eye), which results in the rapid onset of blurred vision, teary eyes, and light sensitivity. In long-standing disease, glaucoma, cataracts, and blindness can occur. Dry eyes are very frequent in long-standing sarcoidosis, even when there is no remaining inflammation. They can be treated with eye drops.
Because some sarcoid-related eye problems do not cause symptoms, it is important that all patients with sarcoidosis have at least yearly appointments with an ophthalmologist.

What are symptoms of sarcoidosis when it affects the musculoskeletal system?

Approximately 10% to 15% of patients may have bone and muscle symptoms, resulting in arthritis, changes in bone structure, or muscle discomfort and pain.

What are symptoms of sarcoidosis when it affects the nervous system?

Neurologic disease occurs in 5% to 10% of patients, often without symptoms in other organs. Symptoms of neurologic involvement include headaches, meningitis, seizures, and nerve tissue degeneration or inflammation – which results in muscle weakness, pain, and numbing or tingling sensations in the face, arms, and legs.

A more recently-discovered type of neurosarcoidosis is small fiber neuropathy (SFN). SFN causes a loss of some types of nerve fibers and requires specialized testing to identify it. Patients with SFN often note burning pain, sensitivity to touch, palpitations, sweating, flushing, light-headedness, gastrointestinal difficulties, and sexual dysfunction.

What are symptoms of sarcoidosis when it affects the heart?

Heart disease is present in 28% of patients with sarcoidosis, although only about 5% of patients report having any heart-related symptoms. Any part of the heart's structure may be affected by granuloma formation. The most frequently diagnosed heart problems include chest pain, cor pulmonale (an enlargement of the right side of the heart that results from disease in the lungs or its blood vessels), cardiomyopathy (disease of the heart muscle itself), and abnormalities in the heart's electrical system, which can result in heart block, dysrhythmias, and sudden death. It is vital to notify your doctor immediately if you start to develop palpitations or dizzy spells, as this may be the first sign of cardiac involvement. Everyone diagnosed with sarcoidosis should have a baseline EKG (heart tracing).

What are symptoms of sarcoidosis when it affects the liver?

Granulomas are present in the liver in 50% to 80% of patients with sarcoidosis. However, patients usually do not notice the symptoms due to liver involvement. Rarely, liver disease can progress to hypertension in the liver (called portal hypertension) or cirrhosis (a disease causing widespread disruption of liver function).

What are symptoms of sarcoidosis when it affects the renal and endocrine system?

Abnormalities can occur in the way the body handles calcium. For example, hypercalcemia (an excess of calcium in the blood) occurs in 2% to 10% of patients. Hypercalciuria (an excess amount of calcium in the urine) occurs in up to 21% of patients. Kidney stone formation, damage to the structure of the kidney itself, and kidney failure may also occur. Another endocrine abnormality seen in sarcoidosis is hypopituitarism. The pituitary gland is at the base of the brain and secretes eight different hormones. The signs and symptoms of hypopituitarism vary, depending on which hormones are undersecreted. Occasionally, there is decreased secretion of all the hormones and this is called panhypopituitarism. Diabetes can occur as a complication of sarcoidosis therapy.

What are symptoms of sarcoidosis when it affects the reproductive system?

Sarcoidosis can affect the male reproductive system, particularly the testes, and may cause male infertility and erectile dysfunction. The disease rarely affects the female reproductive system. Sarcoidosis does not increase the incidence of fetal or maternal complications during pregnancy, unless it has caused severe impairment of the heart or lungs. However, the disease may worsen after childbirth.

What are symptoms of sarcoidosis when it affects organs such as the spleen?

Cytopenias (deficiencies in the amounts of certain blood cells) are the most common "miscellaneous" symptom. Involvement of the spleen or bone marrow may lead to anemia and other blood abnormalities. These conditions usually are not of clinical significance. Bone thinning (osteopenia) is also common in sarcoidosis, as a result of the disease or as a side effect of prednisone therapy.

Some very common conditions seen in those with sarcoidosis are depression, fatigue, and obstructive sleep apnea. Often, these are the most significant problems affecting the quality of life. Depression may occur in up to 2/3 of patients with sarcoidosis, and can cause much of the fatigue that people with sarcoidosis experience. Sleep apnea is suspected in individuals with fatigue, excessive daytime sleepiness, or an unrefreshed feeling on awakening in the morning. Most individuals snore, or experience episodes of choking or gasping at night. Sarcoidosis of the sinuses or nose, weight gain from steroids, and lupus pernio are three factors that increase the chances for obstructive sleep apnea. If your doctor suspects sleep apnea, it may be diagnosed by overnight monitoring in a sleep lab. This sleep test is called a polysomnogram.

What causes sarcoidosis?

The exact cause of sarcoidosis is not known. The disease can appear suddenly and then disappear, or it can develop gradually and produce symptoms that come and go for a lifetime.

Researchers believe that the disease is caused by an abnormal immune response. (The body’s defense system does not react as it should to a foreign substance "intruder.") In a healthy person, inflammation occurs as the cells of the body’s immune system come together to fight the intruder at an organ or tissue site. In a person with sarcoidosis, however, cells that come to fight end up clumping together into small lumps called granulomas.

It’s still uncertain which foreign substance "triggers" the body’s abnormal response. Some researchers suggest that fungi, viruses, or bacteria are likely triggers. In fact, cases of sarcoidosis have occurred in groups of people who had close contact with each other, as well as in recipients of heart, lung and bone marrow transplants. But, so far, no data have been able to convincingly and consistently establish this "infectious" connection as the cause of the disease. However, some types of bacteria have recently emerged as possible candidates and continue to be closely studied.

What are the symptoms of sarcoidosis?

The symptoms of sarcoidosis can vary greatly from individual to individual, and depend on which tissues and organs are affected. In some people, symptoms may begin suddenly and/or severely and subside in a short period of time.

Others may have no outward symptoms at all, even though organs are affected. Still others may have symptoms that appear slowly and subtly, but last or recur over a long time span.

Most common initial symptoms:

• Shortness of breath (dyspnea).
• Cough that won’t go away.
• Reddish bumps or patches on the skin or under the skin.
• Enlarged lymph glands in the chest and around the lungs that produces cough and shortness of breath.
• Fever, weight loss, fatigue, night sweats, general feeling of ill health.

Other disease characteristics include:

• Red and teary eyes or blurred vision.
• Swollen and painful joints.
• Enlarged lymph glands in the neck, armpits and groin.
• Nasal stuffiness and hoarse voice.
• Pain in the hands, feet, or other bony areas due to the formation of cysts (an abnormal sac-like growth) in bones.
• Kidney stone formation.
• Development of abnormal or missed beats (arrhythmias), inflammation of the covering of the heart (pericarditis), or heart failure
• Nervous system effects include hearing loss, meningitis, seizures or psychiatric disorders (for example, dementia, depression, psychosis).

DIAGNOSIS AND TESTS

How is sarcoidosis diagnosed?

Because the symptoms and laboratory findings associated with sarcoidosis can occur in other diseases, there is no single test that can diagnose it. However, the classic sign of the disease is the formation of granulomas (abnormal masses or nodules consisting of inflamed tissue) in one or more of the major organs of the body. Sarcoidosis-related granulomas are not different from granulomas that occur in other diseases. As a result, a complete physical exam and medical history – including occupational history, medication history, and environmental exposures – must be made before concluding that the illness is, in fact, sarcoidosis.

What types of tests are used to diagnose sarcoidosis?

The main tools your doctor will use to diagnose sarcoidosis include:

• Chest X-rays: This test provides a picture of the lungs, heart and surrounding lymph nodes, and reveals where infection-fighting white blood cells have formed – often, the first indication of sarcoidosis. An X-ray can also show how much of the lungs are affected by the disease. Chest X-ray findings fall into one of the following 5 patterns described in the chart below. It is important to know that these X-ray patterns do not represent disease stages (in other words, they are not the sequential steps in the disease course). The categories simply allow doctors to classify the "types of disease."

Chest X-ray patterns

0 = Normal: chest X-ray.

I = Bilateral hilar lymphadenopathy (BHL): the X-ray shows an equal degree of enlargement of lymph nodes at the “root” of both sides of the lungs. This is a common presentation of sarcoidosis.

II = BHL plus pulmonary infiltrations: the X-ray shows a disease process as described above with expansion into and throughout additional lung tissue.

III = Pulmonary infiltration only (without BHL): the X-ray shows a disease process that is spread throughout the lung tissue (with no enlargement of lymph nodes).

IV = Pulmonary fibrosis: the X-ray shows small lung fields, scarring, and “retraction” of both hila (the area at the “root” of the lungs). This type of disease is the most severe or permanent form of the disease.

• Bronchoscopy: Bronchoscopy involves passing a small tube (bronchoscope) down the trachea (windpipe) and into the bronchial tubes (airways) of the lungs. The purpose of this test is to inspect the bronchial tubes and to extract a biopsy (a small tissue sample) to look for granulomas, and to rule out infection. Bronchoscopy is a safe, low risk, outpatient procedure that provides your doctors with a good chance of making an accurate diagnosis. To prepare for this test, you will be asked not to eat or drink anything by mouth for 8 hours before the exam. Prior to the start of the exam, medications will be given to you to help you relax. Because these medications can make you groggy, an adult who can drive you home must accompany you. You will not be allowed to drive. The procedure usually lasts 15 to 45 minutes, with several additional hours for recovery. Your doctor may perform a bronchoalveolar lavage (washing out the air sacs), biopsies of the air sacs or airway wall using a forceps, or biopsy of a lymph node using a needle that is inserted through the bronchoscope. Guidance of the needle with an ultrasound probe attached to the bronchoscope (endobronchial ultrasound or EBUS) can almost always lead to a diagnosis of sarcoidosis when it is present.
• CT scan: This test is another form of X-ray that provides an even more detailed look at the lungs and lymph glands than that provided by a routine chest X-ray. This test does not hurt and simply involves lying on a table for about 10 minutes.
• Mediastinoscopy: This is a surgical procedure that involves a small incision at the base of the neck through which an instrument is passed to biopsy lymph nodes in the chest cavity. This test is performed under general anesthesia in the operating room of a hospital and takes 1 to 2 hours (same day procedure). The need for mediastinoscopy to make a diagnosis has gone down dramatically as EBUS-guided biopsies have become widespread.
• Pulmonary function (breathing) tests: These tests measure how well the lungs are working (expanding and exchanging oxygen and carbon dioxide in the blood). One pulmonary function test uses a device called a spirometer. This device records the changes in air flow as a person inhales and exhales, as well as the overall volume of air exhaled. The development of granulomas and fibrosis of the lung tissue stiffen the lung tissue and destroy the air sacs, making it more difficult for the lungs to perform these tasks.
• Other biopsies: In addition to the bronchoscopic biopsy or lymph node biopsy by mediastinoscopy, tissue samples can be taken from any other involved site including other lymph nodes, skin, and other sites to determine where granulomas have formed.
• Blood tests: Blood analyses evaluate the number and types of blood cells and blood proteins in the body, and how well the cells are functioning. They also track increases in calcium levels and abnormal liver function that sometimes accompany sarcoidosis. One blood test measures a substance called angiotensin-converting enzyme (ACE), which is secreted in large amounts by cells that make up granulomas. ACE levels, however, are not always high in sarcoidosis patients, and increased ACE levels can also show up in other illnesses. In short, there is no specific blood test to diagnose sarcoidosis. A newer blood test that is sometimes more useful than ACE is a measurement of the soluble interleukin 2 receptor levels (sIL2R).
• Pulse oximetry: This test measures the amount of oxygen in the blood by way of a sensor attached to a patient’s finger. If the oxygen level is low, your doctor may recommend the use of supplemental oxygen.
• Electrocardiogram (EKG or ECG): This is a routine office test that checks the electrical activity of the heart. For this test, electrodes with adhesive pads are attached to the skin of the patient’s chest, arms, and legs. The EKG machine creates a picture, on graph paper, of the electrical impulses traveling through your heart. This screening test helps doctors detect several abnormalities in the heart rhythm.
• PET Scan: In this test, a small amount of radioactive material called F-fluorodeoxyglucose is injected into a vein. This substance collects in the areas where the granulomas have collected. A scanner then detects and records the location and amount of inflammation in the body. This scan will detect inflammation created by conditions other than sarcoidosis so it will be used in combination with other testing.
• Gallium scanning: In this procedure, the radioactive chemical gallium-67 is injected into a vein. The gallium collects in inflamed body tissue. A scan of the body then indicates which tissues and how much tissue is affected. The scan will reveal any type of inflammation occurring in the body, however, and does not necessarily mean the patient has sarcoidosis. Because of this test’s limitations, it is not commonly performed.
• Purified protein derivative: This is a type of skin test that is used to help establish prior exposure or infection with tuberculosis (TB). Since TB is sometimes confused with sarcoidosis, this simple test is frequently performed. In sarcoidosis, this skin test is usually negative or non-reactive.
• Slit-lamp examination: This examination looks at the inside of the eye and is used to detect eye-related problems caused by sarcoidosis.

How is sarcoidosis treated?

There is no cure for sarcoidosis, but the disease may get better on its own over time. Many people with sarcoidosis have mild symptoms and do not require any treatment at all. Treatment, when it is needed, generally falls into two categories—maintenance of good health practices and drug treatment. Good health practices include:

• Getting regular check-ups with your health care provider.
• Eating a well-balanced diet with a variety of fresh fruits and vegetables.
• Drinking 8 to 10 8-ounce glasses of water a day.
• Getting 6 to 8 hours of sleep each night.
• Exercising regularly, and managing and maintaining your weight.
• Quitting smoking.
• Avoiding exposure to dust, chemicals, fumes, gases, toxic inhalants and other substances that can harm your lungs.
• Avoiding excessive amounts of calcium-rich foods (such as dairy products, oranges, canned salmon with bones), vitamin D and sunlight. Daily sunbathing is an example of excessive sunlight and should be avoided; sunlight received from activities of everyday living is acceptable. (The advice in this bullet point is limited to patients with high blood or urine levels of calcium.)

Drug treatments are used to relieve symptoms, reduce the inflammation of the affected tissues, reduce the impact of granuloma development, and prevent the development of lung fibrosis and other irreversible organ damage.

Corticosteroids are particularly effective in reducing inflammation, and are typically the first drugs used in treating sarcoidosis. The oral corticosteroid prednisone is the most commonly used corticosteroid.

For patients with no symptoms or very mild symptoms, the side effects of prednisone therapy may outweigh possible benefits, so treatment is usually not recommended for this disease stage. Corticosteroids are more typically reserved for patients with disease that is of moderate severity. Symptoms, especially cough and shortness of breath, generally improve with steroid therapy.

Corticosteroid treatment controls the disease rather than cures it. The symptoms respond to treatment in the majority of patients. A relatively high dose is usually prescribed at first, followed by a slow taper to the lowest effective dose. Fortunately, disease relapses --when they occur -- usually respond to retreatment with steroids. Patients who improve and remain stable for more than one year after stopping treatment have a low rate of relapse.

Results of some long-term studies indicate patients can expect about a 10% improvement in symptoms up to five years after quitting corticosteroid treatment. Whether or not this is a large enough benefit to outweigh the risks of corticosteroid treatment remains an issue debated by doctors. If steroids are prescribed, the patient should see his or her doctor at regular intervals so that the disease and side effects of treatment can be monitored. The common side effects of corticosteroids include:

• Excessive weight gain.
• Insomnia.
• Acne.
• Diabetes in susceptible people.
• High blood pressure.
• Glaucoma.
• Cataracts.
• Osteoporosis.
• Depression and emotional irritability.
• Skin bruising.
• Increased risk of infections.

Are there alternative treatments to corticosteroids?

Other treatments are available for patients who cannot tolerate steroids either because they are contraindicated or because side effects cannot be tolerated. Patients whose disease does not respond to steroids or who wish to lower the dose of steroids and use another drug in combination have additional treatment options as well.

It's important to keep in mind that all of the following treatments have been used and studied much less extensively than corticosteroids. Doctors with special expertise in sarcoidosis should manage patients who are on regular prednisone therapy or any of the following alternatives:
Methotrexate, leflunomide or azathioprine: These medications, most often used in rheumatoid arthritis, have been used in place of or in addition to corticosteroids to treat pulmonary sarcoidosis and chronic sarcoidosis. Methotrexate can be taken as pills or an injection under the skin, once per week. All of these medications can suppress the immune system and have the potential to cause liver toxicity so blood work needs to be monitored every 4-8 weeks. In addition, these drugs have the potential to harm a fetus (unborn child) so pregnancy needs to be avoided. Patients who take methotrexate must not drink alcohol.
Hydroxychloroquine and chloroquine: These oral antimalarial drugs have been used to treat sarcoidosis of the skin, lungs, and nervous system. They are used to treat the hypercalcemia seen with sarcoidosis. Patients on these drugs need occasional monitoring of their eyes by an ophthalmologist.
Cyclophosphamide or chlorambucil: These medications are usually used for disease that has reached the severe stage and after other therapies have failed. Cyclophosphamide is associated with many severe side effects including bone marrow suppression and kidney damage.
Pentoxifylline and thalidomide: Recent studies have reported beneficial effects of these drugs in treatment-resistant lupus pernio.
Infliximab or adalimumab: These medications, which are given as an intravenous injection every 4-8 weeks or under the skin (subcutaneous injection) every 1-2 weeks, have been used recently for patients with severe sarcoidosis. They are usually used after other options are not successful or not tolerated. They significantly increase the risk for infections.
Various NSAIDs (nonsteroidal anti-inflammatory drugs [such as ibuprofen or aspirin]): These drugs may help reduce acute inflammation and relieve arthritis and fever.
Topical corticosteroids: These agents could be used in several preparations (for example, eye drops, skin creams, and respiratory sprays) for mild local symptoms of sarcoidosis. Although they are a lot safer than steroid pills, they are also less effective.
Organ transplantation: This option is rarely considered in patients with end-stage disease, where the kidneys or lungs have failed.

When is treatment started?

Many questions exist regarding the appropriate timing and duration of treatment for sarcoidosis. The decision to begin treatment generally depends on the organ system involved and the severity of disease.

There are several situations, however, under which some form of treatment is usually given. These include patients with neurological, heart, and sight-threatening disease; those with serious pulmonary symptoms and/or worsening lung function; and those with kidney involvement--specifically, hypercalcemia. Because of the serious effects that can occur when these systems are involved, treatment is started even if symptoms are mild.

Other indications for which treatment could be considered include an inability to work as a result of fever, weakness, fatigue, joint pain, nervous system changes, respiratory symptoms (especially shortness of breath and cough), and disfiguring skin disease.

What can happen as the disease progresses?

In many people with sarcoidosis, the disease appears briefly and then disappears without the person even knowing they have the disease. When sarcoidosis seriously affects the ability of the lungs to function normally, patients may require supplemental oxygen (supplied in a small portable oxygen tank and administered through plastic tubing clipped to the nose) to help them breathe.

Twenty percent to 30% of people have some permanent lung damage. For 10% to 30%, sarcoidosis is a chronic condition, with symptom progression despite treatment that has continued for more than two years. In some people, the disease may result in the deterioration of the affected organ.

When the granulomas or fibrosis seriously affect the function of a vital organ -- such as the lungs, heart, nervous system, liver, or kidneys -- sarcoidosis can be fatal. Death occurs in 1% to 6% of all patients with sarcoidosis and in 5% to 10% of patients with chronic progressive disease. The leading cause of sarcoidosis-related death in the United States is irreversible pulmonary fibrosis.