Sarcoidosis is a disease that involves abnormal collections of inflammatory cells that form lumps known as granulomas. The disease usually begins in the lungs, skin, or lymph nodes. Less commonly affected are the eyes, liver, heart, and brain. However, any organ can be affected. Signs and symptoms depend on the organ involved. There are often no symptoms, or they are only mild.

When it affects the lungs there may be wheezing, coughing, shortness of breath or chest pain. Some may have Lofgren’s syndrome in which there is a fever, large lymph nodes, arthritis, and a rash known as erythema nodosum.

The cause of sarcoidosis is unknown. Some believe it may be due to an immune reaction to a trigger such as an infection or chemicals in those who are genetically predisposed. Those with affected family members are at higher risk. Diagnosis is based in part on signs and symptoms, which may be supported by biopsy. Findings that make it likely include large lymph nodes at the root of the lung on both sides, high blood calcium with a normal level of parathyroid hormone, or elevated levels of angiotensin-converting enzyme (ACE) in the blood. The diagnosis should only be made after excluding other possible causes of similar symptoms, such as tuberculosis.

Sarcoidosis can resolve without any treatment within a few years. However, some people may have a long-term or serious illness. Some symptoms may be improved with the use of anti-inflammatory medications such as ibuprofen. In cases where the condition causes significant health problems, steroids such as prednisone are indicated. Medications such as methotrexate, chloroquine, or azathioprine can sometimes be used to lessen the side effects of steroids. The risk of death is between one and seven percent. There is less than a five percent chance that the disease will come back in someone who has previously had it.

In 2015, pulmonary sarcoidosis and interstitial lung disease affected 1.9 million people worldwide and caused 122,000 deaths. It is more common in Scandinavians, but it occurs in all parts of the world. In the United States, the risk is higher among blacks than whites. It usually begins between the ages of 20 and 50. It occurs more often in women than in men. Sarcoidosis was first described in 1877 by the English physician Jonathan Hutchinson as a painless skin disease.