Inflammation of tissue in one or many parts of the body, most often affecting the lungs, lymph nodes, skin, and eyes
- Most common in young adults
- More common in females
- Sometimes runs in families
- Lifestyle is not a significant factor
In sarcoidosis, areas of inflammation develop on one or more parts of the body, frequently in the lungs. In some cases, only a single type of tissue is affected; in others, the condition affects several different organs. Sarcoidosis is thought to be caused by an abnormal, exaggerated response of the immune system. The trigger for this response is not fully understood, but it is thought that an infection may be involved.
Sarcoidosis may not produce symptoms. If symptoms do develop, they either appear suddenly over a period of a few days (acute sarcoidosis) or progress slowly over several years (chronic sarcoidosis). There is no cure, but symptoms disappear spontaneously in some cases. The condition, particularly in its acute form, is more common in women than in men. Sarcoidosis sometimes runs in families.
What are the symptoms?
Some people who have sarcoidosis never develop symptoms. However, those who have acute sarcoidosis may experience the following symptoms:
Fever and excessive sweating at night.
Pain in the joints.
Painful red lesions on the shins (see Erythema nodosum).
People with chronic sarcoidosis may not experience symptoms initially, but they may gradually develop:
Increasing shortness of breath.
Both acute and chronic sarcoidosis may cause redness of the eyes, blurred vision (see Uveitis), skin lesions on the nose and face, and swelling of the lymph nodes. There may also be high levels of calcium in the blood and/or urine, which may cause nausea and constipation and eventually lead to kidney damage.
How is it diagnosed?
If there are no symptoms, chronic sarcoidosis is usually discovered only after a chest X-ray has been taken for another reason. Sarcoidosis may also be diagnosed by an X-ray taken to investigate symptoms such as coughing and shortness of breath. The X-ray usually shows swollen lymph nodes in the chest or shadows on the lungs. Sarcoidosis may also be diagnosed by the presence of skin lesions and confirmed by an examination of affected tissue from a skin sample or a biopsy taken from the lung or airways during bronchoscopy. You may also have lung function tests and blood tests to measure your calcium levels.
What is the treatment?
There is no cure for sarcoidosis, but your symptoms may be relieved by using corticosteroids (see Corticosteroids for respiratory disease). These drugs are usually effective, although you may need low-dose treatment for several years if you have chronic sarcoidosis. Corticosteroids may be used for serious complications such as uveitis. You may need regular blood tests, chest X-rays, and lung function tests to monitor your response to treatment.
What is the prognosis?
In about 8 in 10 affected people, most commonly those with acute sarcoidosis, the disorder clears up spontaneously within 3 years. Sarcoidosis is progressive in only about 1 in 10 people with the disorder, and it proves fatal in only about 2 in 100 people.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.
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