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Sarcoidosis is an immune system disorder that can attack any organ of the body. However, it most frequently starts in the lungs and lymph nodes, particularly those in the chest cavity. Sarcoidosis is characterized by the presence of small (microscopic) areas or lumps of inflamed cells called granulomas. The granulomas can grow and form larger clusters within an organ and may affect the function of that organ. Granulomas can be found inside the body, for example, on the walls of the bronchi and bronchioles (breathing tubes) in the lungs. They can also appear as sores on the skin. Sarcoidosis also affects the eyes and liver and less often, the spleen, nerves, heart, brain, salivary glands, tear glands, bones and joints.
The exact cause is not known. Research suggests that a combination of genetics and environmental factors may play a role.
Sarcoidosis causes a variety of symptoms or no symptoms at all. It is not contagious. Symptoms vary depending on which organs are affected.
General symptoms may include fatigue, swollen lymph nodes, weight loss, and pain and swelling in the joints (e.g., ankles).
Patients suffering from pulmonary (lung) sarcoidosis may have a persistent dry cough, shortness of breath, wheezing, and chest pain.
Skin issues may include
- rash of red or purple-red bumps, often near the shins or ankles
- disfiguring sores on the nose, cheeks, and ears
- areas of the skin that are lighter or darker in colour
- growths under the skin, particularly around scars or tattoos
Sarcoidosis can also affect the eyes without causing any symptoms. When eye symptoms do occur, they may include eye pain, blurred vision, severe redness, and sensitivity to light. Burning, itching or dry eyes may also occur.
Heart issues may include:
- chest pain
- shortness of breath
- irregular heartbeats
- rapid or fluttering heart beat
- swelling caused by excess fluid
Nervous system issues may include:
- increased thirst or amounts of urine
- weak or paralyzed facial muscles
The diagnosis of sarcoidosis is based on the patient's medical history, physical examinations, laboratory tests, lung function studies, chest x-rays, CT scans, eye exams, and other medical tests. The diagnosis is confirmed by eliminating other diseases having similar symptoms and performing a biopsy on any of the affected organs. Sarcoidosis is not a type of cancer.
Sarcoidosis usually occurs between the ages of 20 to 40 years. People of African and Northern European descent are more likely to have sarcoidosis. It affects both men and women but studies show it is more likely to occur in women. People with a family history of sarcoidosis are more likely to develop the disease.
Many patients recover completely without treatment. When therapy is recommended, drugs are used to reduce inflammation or suppress the immune system.
The link between sarcoidosis and work has not been established.
- Fact sheet last revised: 2023-05-01