Sarcoidosis Health Article

Definition

Sarcoidosis is a disease which can affect many organs within the body. It causes the development of granulomas. Granulomas are masses resembling little tumors. They are made up of clumps of cells from the immune system.

Description

Sarcoidosis is a very puzzling disorder. In addition to having no clear-cut understanding of the cause of sarcoidosis, researchers are also puzzled by its distribution in the world population. In the United States, for example, 10-17 times as many African-Americans are affected as white Americans. In Europe, whites are primarily affected.

Prevalence is a way of measuring the number of people affected per 100,000 people in a given population. The prevalence figures for sarcoidosis are very unusual. In the United States, prevalence figures range from five (5/100,000 in the United States) for whites to 40 for blacks. In Europe, prevalence ranges from three in Poland, to 10 in France, to 64 in Sweden, to 200 for Irish women living in London. Furthermore, a person from a group with very low prevalence who leaves his or her native land for a second location with a higher prevalence will then have the same risk as anyone living in that second location.

Sarcoidosis affects both men and women, although women are more likely to have the disorder. The average age for diagnosis is around 20-40 years.

Causes and symptoms

The cause of sarcoidosis is not known. Because the granulomas are primarily made up of cells from the immune system (macrophages and lymphocytes), an immune connection is strongly suspected. One of the theories which has been put forth suggests that exposure to some toxic or infectious material starts up an immune response. For some reason, the body is unable to stop the response, and it spreads from the original organ to other organs.

Because sarcoidosis has been noted to occur in family groups, a genetic cause has also been suggested. Research shows that identical twins are more likely to both have sarcoidosis than are nonidentical twins or other siblings.

Some cases of sarcoidosis occur without the patient even noting any symptoms. These cases are often discovered by chance during routine chest x rays. Most cases of sarcoidosis, however, begin with very nonspecific symptoms, such as decreased energy, weakness, and a dry cough. Occasionally, the cough is accompanied by some mild pain in the breastbone (sternum). Some patients note that they are having unusual shortness of breath while exercising. Some patients develop fever, decreased appetite, and weight loss.

Virtually every system of the body has the potential to suffer the effects of sarcoidosis:

• tender reddish bumps (nodules) or patches often appear on the skin
• the eyes may become red and teary, and the vision blurry
• the joints may become swollen and painful (arthritis)
• lymph nodes in the neck, armpits, and groin become enlarged and tender, lymph nodes within the chest, around the lungs, also become enlarged
• fluid may accumulate around the lungs (pleural effusion), making breathing increasingly difficult
• nasal stuffiness is common, as well as a hoarse sound to the voice
• cysts in the bone may cause pain in the hands and feet, or in other bony areas
• the bone marrow may decrease the production of all blood cells; decreased number of red blood cells causes anemia, fewer white blood cells increases the chance of infections, fewer platelets can increase the chance of bleeding
• the body's ability to process calcium often becomes abnormal, so that excess calcium passes through the kidneys and into the urine; this may cause kidney stones to form
• the liver may become enlarged
• the heart may suffer a variety of complications, including abnormal or missed beats (arrhythmias), inflammation of the covering of the heart (pericarditis), and an increasing tendency toward weak, ineffective pumping of the blood (heart failure)
• the nervous system may display the effects of sarcoidosis by hearing loss, chronic inflammation of the coverings of the brain and spinal cord (meningitis), abnormalities of the nerve that is involved in vision (optic nerve dysfunction), seizures, and the development of psychiatric disorders

Any, all, or even none of the above symptoms may be present in sarcoidosis.