Sarcoidosis
Description
Sarcoidosis (also: sarcoid) is an inflammatory disease that affects the entire body - i.e. it is systemic. Microscopically small tissue nodules called granulomas are formed, which can occur almost anywhere in the body. The lungs are most frequently affected. The granulomas impede organ function and provoke changes in connective tissue (fibrosis). Sarcoidosis is a relatively rare disease. The number affected is between 1 - 60 people of every 100,000, with strong regional variations. Sarcoidosis is more prevalent in northern countries than southern ones.
Symptoms
A distinction is made between occurrences of the initially acute form of sarcoidosis, so-called Löfgren syndrome (30% of cases), and the onset of the insidious and chronic form of the disease (70% of cases). Each form differs in its symptoms. The acute course is marked by the presence of fever, arthralgia (painful joints), night sweats, acute arthritis, erythema nodosum (inflammation under the skin), dry cough, dyspnea (laboured breathing) when under stress, and swollen lymph nodes between the lungs. The chronic course manifests itself subtly over a period of months in slowly increasing dyspnea during stress, possible fatigue and weakness at first, weight loss, persistent dry cough, and arthralgia whose intensity unpredictably increases or decreases.
Causes and Risks
The causes of sarcoidosis are poorly understood. There is probably a genetic predisposition to the disease. In addition, researchers suspect that the granulomas develop as a result of the body's excessive immune response. Tissue examinations show that the nodules consist mainly of immune system cells.
Examination and Diagnosis
In cases of suspected sarcoidosis, a conventional chest X-ray should be taken and a pulmonary function test performed. If the X-ray images indicate characteristic changes, the doctor orders more tests: bronchoscopy, bronchoalveolar lavage to flush the bronchial system in acute inflammation, and blood tests - Angiotestin-converting enzyme (ACE) and C-reactive protein (CRP). In case of an uncertain diagnosis, and in order to exclude other lung diseases, computed tomography (CT) is sometimes useful.
Treatment
No causal therapy for sarcoidosis exists. In up to 60% of sarcoidosis cases there is spontaneous remission. The symptoms can be treated symptomatically. For severe pain, nonsteroidal anti-inflammatory drugs such as aspirin, diclofenac or ibuprofen are taken. If the organs are symptomatically involved, cortisone therapy is performed, for example in case of limited lung function. For very severe forms of sarcoidosis, other medications will be considered in addition to cortisone: immunosuppressive agents such as methotrexate, azathiopin, cyclophosphinad, TNF-alpha blockers or chloroquine - a drug that is normally used against malaria. Because these drugs can sometimes have serious side effects, the potential advantages and disadvantages should be discussed in detail with the doctor before starting treatment.
Course and Prognosis
Sarcoidosis usually has a favorable prognosis. With the acute form, 90 percent of cases end in spontaneous remission. After recovery, approximately 30 percent of patients still suffer from decreased lung function or lingering damage to other affected organs. 10 percent of those affected develop progressive pulmonary fibrosis. In a few cases, potentially fatal complications can occur.
Miscellaneous/Other Comments
Because of its rarity, the disease is often discovered only after a long diagnostic process. In particular, suspected sarcoidosis must be differentiated from pulmonary tuberculosis, a lung tumor or lymphoma.