Sarcoidosis is a disease in which inflammation occurs in the lymph nodes, lungs, liver, eyes, skin, or other tissues.
Causes, incidence, and risk factors
The cause of the disease is unknown. In sarcoidosis, tiny clumps of abnormal tissue (granulomas) form in certain organs of the body. Granulomas are clusters of immune cells.
The disease can affect almost any organ of the body, but it most commonly affects the lungs.
Possible causes of sarcoidosis include:
Extreme immune response to infection
High sensitivity to environmental factors
Genetic factors
The condition is more common in African Americans than Caucasians, especially in Caucasians of Scandinavian heritage. Females are usually affected more often than males.
The disease typically begins between ages 20 and 40. Sarcoidosis is very rare in young children.
A person with a close blood relative who has sarcoidosis is nearly five times as likely to develop the condition.
Symptoms
There may be no symptoms. When symptoms occur, they can involve almost any body part or organ system in your body.
To diagnose this condition, a biopsy is needed. Biopsy of the lung using bronchoscopy is usually done. Biopsies of other body tissues may also be done.
This disease may affect the results of the following lab tests:
Sarcoidosis symptoms will often get better on their own slowly without treatment.
Patients whose eyes, heart, nervous system, or lungs are involved may need to be treated with corticosteroids (prednisone or methylprednisolone). Therapy may continue for 1 or 2 years. The most severely affected patients may need lifelong therapy.
Drugs that suppress the immune system (immunosuppressive medicines) are sometimes also needed:
The drug used most often is methotrexate, but azathioprine and cyclophosphamide are also sometimes recommended.
Hydroxychloroquine is useful for skin sarcoidosis.
Rarely, some people with end-stage heart or lung damage may need an organ transplant.
Expectations (prognosis)
Many people with sarcoidosis are not seriously ill, and the disease may get better without treatment. About 30 - 50% of cases get better without treatment in 3 years. About 20% of people whose lungs are involved will develop lung damage.
The overall death rate from sarcoidosis is less than 5%. Causes of death include:
Bleeding from the lung tissue
Heart damage, leading to heart failure and abnormal heart rhythms
Weinberger SE. Sarcoidosis. Goldman L, Ausiello D. Cecil Textbook of Medicine. 23rd ed. Philadelphia, Pa:Saunders Elsevier; 2007:chap 95.
Review Date:
6/2/2011
Reviewed By:
David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; and Denis Hadjiliadis, MD, Assistant Professor of Medicine, Division of Pulmonary, Allergy and Critical Care, University of Pennsylvania, Philadelphia, PA. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
