Sarcoidosis is a disease mainly affecting the lungs and the lymph nodes (glands) next to the lungs. It causes a specific type of inflammation (granulomas) that can lead to enlargement of the glands and damage to lung tissue, especially scarring in the upper parts of the lungs.
The cause of sarcoidosis is not known. It is not started by an infection, vaccination, chemicals or exposure to something at work. The body's immune system starts over working and the resulting inflammation causes damage to tissues.
It often starts in early adult life, and affects both men and women. In the lungs it can cause cough and shortness of breath. It often affects other parts of the body, especially glands in the neck, eyes, skin and liver.
Most people with sarcoidosis have very mild or no symptoms at all. It is not uncommonly found by accident on an x-ray. Very often patients with sarcoidosis have no significant problem (symptoms, x-ray changes or damage to other organs), and monitoring the disease to make sure about this is all that is required.
In a small proportion (less than 30%) of patients with sarcoidosis, treatment is required. This is usually because the symptoms are bad enough or there is evidence that the disease is causing increasing damage. The diagnosis usually requires a CT scan of the chest, lung function tests, blood tests and occasionally a biopsy of the lung. Treatment is with medication to stop the inflammation, most often prednisolone. It needs to be done by a specialist physician to make sure that it is effective and side effects are minimized.
Very rarely sarcoidosis causes serious illness and treatment is difficult, but for nearly all patients it causes no trouble at all or is responsive to treatment lasting for 3 - 24 months and with minimal long-term consequences.