Sarcoidosis is a rare disease that causes inflammation and scar tissue throughout the body, especially the lungs, lymph nodes, liver, skin, and eyes.

The cause of sarcoidosis is not known. It occurs most often in young and middle-aged adults.

Symptoms may include fever, body aches, swelling of the lymph glands, breathlessness, a reddish rash on the face or low down on the legs, painful joints, and numbness. But sometimes sarcoidosis does not cause any symptoms. It may lead to lung (respiratory) failure and heart problems in some cases.

Sarcoidosis may require long-term treatment (lasting months to years) with corticosteroids and other medicines, especially if it causes severe breathing problems or affects the brain and heart.