Sarcoidosis is a disease characterized by a specific type of inflammation of various tissues of the body. Sarcoidosis can appear in almost any body organ, but it starts most often in the lungs or lymph nodes. As sarcoidosis progresses, microscopic lumps of a specific form of inflammation, called granulomas, appear in the affected tissues. In the majority of cases, these granulomas clear up, either with or without treatment. In the few cases in which the granulomas do not heal and disappear, the tissues involved tend to remain inflamed and become scarred (fibrotic). In addition to the lungs and lymph nodes, the organs more likely than others to be affected by sarcoidosis are the liver, skin, heart, nervous system, and kidneys, in that order of frequency.
Sarcoidosis is sometimes named according to the organ involved.
The cause of sarcoidosis is unknown. Sarcoidosis is currently thought to be associated with an abnormal immune response.
Sarcoidosis can appear suddenly and disappear. Alternatively, it can develop gradually and go on to produce symptoms that come and go, sometimes for a lifetime.
The symptoms of sarcoidosis depend on what areas of the body are affected.
More generalized symptoms of sarcoidosis include:
It is important to note that sarcoidosis is usually not crippling. It often goes away by itself, often healing in 24 to 36 months. Even when sarcoidosis lasts longer, most patients can go about their lives as usual.
Anyone with the symptoms of shortness of breath and persistent cough should have an evaluation by a health care professional. Furthermore, those with a persistent rash, weight loss, fatigue, night sweats, and/or fever should have a medical examination. Moreover, patients with a known diagnosis of sarcoidosis should have a medical follow-up.
The 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:
No single test can be relied on for a correct diagnosis of sarcoidosis. An old test used for the diagnosis of sarcoidosis called the Kveim test is no longer in use for several reasons. X-rays and blood tests are usually the first procedures the doctor will order. Pulmonary function tests often provide clues to diagnosis. Other tests may also be used, some more often than others.
The biopsy of a tissue sample of an involved organ is the ultimate test to confirm the diagnosis. Many of the tests that the doctor uses to help diagnose sarcoidosis can also help the doctor follow the progress of the disease, and determine whether the sarcoidosis is getting better or worse. The following are commonly used tests in the evaluation of a patient with sarcoidosis.
The chest X-ray is often helpful to give the doctor a picture of the lungs, heart, as well as surrounding tissues containing lymph nodes (where infection-fighting white blood cells form) and give the first indication of sarcoidosis. For example, a swelling of the lymph glands between the lungs can show up on an X-ray. An X-ray can also show which areas of the lung are affected.
By performing a variety of tests called pulmonary function tests (PFTs), the doctor can find out how well the lungs are doing their job of expanding and exchanging oxygen and carbon dioxide with the blood. The lungs of patients with sarcoidosis cannot handle these tasks as well as they should; this is because granulomas and fibrosis of lung tissue decrease lung capacity and disturb the normal flow of gases between the lungs and the blood. One PFT procedure calls for the patient to breathe into a machine called a spirometer. It is a mechanical device that records changes in the lung size as air is inhaled and exhaled, as well as the time it takes the patient to do this.
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 often 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, these enzyme levels are often high in patients with sarcoidosis. Blood ACE levels, however, are not always elevated in people with sarcoidosis, and increased ACE levels can also occur in other illnesses.
This test 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 number 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 indicates an inflammation in the lungs.
Microscopic examination of specimens of lung tissue obtained with a bronchoscope, or of specimens from other tissues, can tell a doctor where granulomas have formed in the body and can provide the ultimate diagnosis.
In this procedure, the doctor injects the radioactive chemical element gallium-67 into the patient's vein. The gallium collects at places in the body affected by sarcoidosis and other inflammatory conditions. Two days after the injection, the body is scanned for radioactivity. Increases in gallium uptake at any site in the body indicate that inflammatory activity has developed at the site and 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.
An instrument called a slit lamp, which permits examination of the inside of the eye, can be used to detect silent eye damage from sarcoidosis.
Fortunately, many patients with sarcoidosis require no treatment. Symptoms, after all, are usually not disabling and do tend to disappear spontaneously.
When therapy is recommended, the main goal is to keep the lungs and other affected body organs working and to relieve symptoms. The disease is considered inactive once the symptoms fade.
The doctor's decision depends on the organ system involved and how far the inflammation has progressed. If the disease appears to be severe, especially in the lungs, eyes, heart, nervous system, spleen, or kidneys, the doctor may prescribe corticosteroids. There is no treatment at present to reverse the lung scarring (fibrosis) that might be present in advanced sarcoidosis.
If one has sarcoidosis, one can help themselves by following sensible health measures.
Occasionally, a blood test will show a high blood level of calcium accompanying sarcoidosis. The reasons for this are not clear. When it does occur, the patient may be advised to avoid calcium-rich foods, vitamin D, or sunlight, or to take prednisone (this corticosteroid usually quickly reverses the condition). If a high blood calcium level (hypercalcemia) is detected, avoiding these supplements can provide additional natural treatment methods for sarcoidosis.
Attention to each organ affected is necessary for optimal management of the disease. This requires medical evaluation of lung, heart, kidney, skin, brain, and nervous system function. Medical treatments must be directed toward correcting the effects of dysfunction in each of these organs.
Corticosteroids, such as prednisone and prednisolone, are the mainstay of the treatment of sarcoidosis. Corticosteroid treatment usually results in improvement. Symptoms often start up again, however, when it is discontinued. Treatment, therefore, may be necessary for several years, sometimes for as long as the disease remains active or to prevent relapse.
In addition to corticosteroids, various other drugs have been tried, but their effectiveness has not been established in controlled studies. These drugs include chloroquine (Aralen) and D-penicillamine. Several drugs such as chlorambucil (Leukeran), azathioprine (Imuran), methotrexate (Rheumatrex, Trexall), and cyclophosphamide (Cytoxan), might suppress alveolitis (inflammation of the air sacs of the lungs) by killing the cells that produce granulomas, have also been used. None have been adequately evaluated in controlled clinical trials, and the risk of using these drugs must be weighed closely against the benefits of preventing organ damage by the disease. They should not be used by pregnant women.
Cyclosporine, a drug used widely in organ transplants to suppress the immune reaction, has been evaluated in one controlled trial and was found to be unsuccessful in the treatment of sarcoidosis in this study. More recently, thalidomide (Thalomid) has been used successfully in a limited number of patients and seemed to improve lung function and heal skin lesions. Infliximab (Remicade) has been reported recently as effective in treating patients with sarcoidosis.
For difficult-to-treat (refractory) sarcoidosis and sarcoidosis involving the nervous system (neurosarcoidosis), recent research using biologic medications that inhibit tumor necrosis factor (TNF-blockers) has been found in some studies to be beneficial. The TNF-blockers used were adalimumab (Humira) and infliximab (Remicade).
Frequent check-ups are important so that the doctor can monitor the illness and, if necessary, adjust the treatment. Corticosteroids, for example, can have side effects:
Long-term use can affect the stomach, skin, and bones. This situation can bring on stomach pain, an ulcer, or acne, or cause the loss of calcium from bones. However, if the corticosteroid is taken in carefully prescribed low doses, the benefits from the treatment are usually far greater than any associated side effects.
The cause of sarcoidosis still remains unknown, so there is at present no known way to prevent or cure this disease.
Night sweats generally are a symptom of an underlying problem that may require medical treatment. However, typically treatment is not directed at the night sweats themselves, but rather at the underlying cause, for example:
