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.
There may be no symptoms. When symptoms occur, they can involve almost any body part or organ system in your body.
Almost all patients have lung or chest symptoms:
- Chest pain (most often behind your breast bone)
- Dry cough
- Shortness of breath
Symptoms of general discomfort or uneasiness often occur:
- Fatigue (one of the most common symptoms in children)
- Joint achiness or pain (arthralgia)
- Overall feeling of discomfort, illness, or lack of well-being
- Weight loss (one of the most common symptoms in children)
- Hair loss
- Raised, red, firm skin sores (erythema nodosum), almost always on the front part of the lower legs
- Scars that become raised or inflamed
Nervous system symptoms may include:
- Weakness on one side of the face
Eye symptoms include:
- Discharge from the eye
- Dry eyes
- Vision loss
Other symptoms of this disease:
- Dry mouth
- Fainting spells if the heart is involved
- Swelling in the upper part of the abdomen
Signs and tests
A physical exam may show the following:
- Abnormal breath sounds (such as rales)
- Enlarged liver
- Enlarged lymph glands
- Enlarged spleen
Often the disease is found in patients with visible physical signs who have an abnormal chest x-ray.
Different imaging tests may help diagnose sarcoidosis:
- Chest x-ray to see if the lungs are involved or lymph nodes are enlarged
- CT scan of the chest
- Lung gallium scan
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:
- Calcium levels (urine, ionized, serum)
- Immunoelectrophoresis - serum
- Liver function tests
- Quantitative immunoglobulins (nephelometry)
- Serum phosphorus
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.
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
- Lung scarring (pulmonary fibrosis)
- Fungal lung infections (aspergilloma)
- Glaucoma and blindness from uveitis (rare)
- Kidney stones from high calcium levels in blood or urine
- Osteoporosis and other complications of taking corticosteroids for long periods of time.
- Pulmonary hypertension
Calling your health care provider
Call your health care provider if you have:
- Difficulty breathing
- Vision changes
- Other symptoms of this disorder
Drake W, Newman LS. Sarcoidosis. In: Mason RJ, Broaddus VC, Martin Tr, et al, eds. Murray and Nadel's Textbook of Respiratory Medicine. 5th ed. Philadelphia, Pa: Saunders Elsevier; 2010:chap 59.
Iannuzzi MC, Rybicki Ba, Teirstein AS. Sarcoidosis. N Engl J Med. 2007;357:2153-2165.
Weinberger SE. Sarcoidosis. Goldman L, Ausiello D. Cecil Textbook of Medicine. 23rd ed. Philadelphia, Pa:Saunders Elsevier; 2007:chap 95.