Sarcoidosis is an inflammatory disease that starts in your lungs, but in time it can affect virtually any organ in your body, including your liver, skin, heart, nervous system and eyes. Sarcoidosis can attack any organ and often affects more than one. However, more than 90 percent of patients with sarcoidosis will have pulmonary involvement. Pulmonary sarcoidosis can cause loss of lung volume (the amount of air the lungs can hold) and abnormal lung stiffness.
The cause of sarcoidosis is unknown. Because the lungs and thoracic lymph nodes (the lymph nodes located in the chest) are the most frequently involved organs, some physicians and researchers suspect that sarcoidosis may be caused by something that enters the body through the lungs, that is, something that is inhaled such as a virus or bacteria, or an unidentified environmental toxin.
Possible causes of sarcoidosis include:
* Hypersensitivity to environmental factors
* Extreme immune response to infection
The incidence varies widely according to race and sex.
It is more common in African Americans than Caucasians. Females are usually affected more frequently than males. Onset of the disease typically occurs between the ages of 20 and 40. Sarcoidosis is very rare in young children.
As with many diseases, sarcoidosis is often present without causing any symptoms. However, when symptoms do appear they do so abruptly (acute sarcoidosis), or gradually over a number of years (chronic sarcoidosis). About 25% of people who have sarcoidosis have eye symptoms. These symptoms can make it hard to see, but they rarely cause blindness. Eye symptoms usually include dry eyes, but they can also include swelling of the tear gland that makes the eyes water.
Pulmonary function tests evaluate how well the lungs are functioning (i.e., how well the lungs expand and how much oxygen they are capable of handling). Sarcoidosis patients who have granulomas or fibrosis in their lungs generally do not perform as well as they should on these tests.
Because the cause sarcoidosis is unknown, it is difficult to treat. The symptoms of sarcoidosis result from inflamed granuloma tissue and can be relieved, to some extent, by drugs that stop the swelling in particular, corticosteroids. The dose and duration of corticosteroid treatment varies considerably from case to case. The most common corticosteroid is prednisone.