Sarcoidosis

What is Sarcoidosis? Sarcoidosis (sar-koy-DO-sis) is a chronic, multi-system inflammatory disorder of unknown cause. In this disease, there is granulomatous (nodule-like) inflammation of the affected organ(s), most commonly the lymph nodes, lungs and liver. Although no specific cause has ever been identified, there is scientific evidence that it may result from certain genetic factors and environmental agents.

Who gets it? The onset of this condition is usually between the ages of 20 and 40, with a peak around 25. It occurs worldwide and can affect both sexes and all races. In the US, Sarcoidosis is much more common in African Americans than Caucasians and slightly more common in women than men. Manifestations of the disease seem to be related to race and gender. For example, Caucasians are more likely to have less severe disease. Interestingly, Sarcoidosis is one of the few pulmonary conditions more common in nonsmokers than smokers.

What are the symptoms? Sarcoidosis can affect virtually any organ, but lymph glands, lungs and liver are the most commonly affected. Lung involvement may be seen in 90% and liver in up to 80% of cases. Other common sites include skin, heart, musculoskeletal system, central nervous system, eyes, spleen and salivary glands. Symptoms are usually of gradual onset, but may be abrupt. Some have no symptoms. Non-specific symptoms, such as fatigue, malaise, lack of energy, weight loss, generalized aches and pains, fever, and joint pains or stiffness are common.

sarcoidosis

Other symptoms relate to the organ or organs affected. With lung involvement, dry hacking cough, and shortness of breath (especially with exertion) are frequent. It may also cause chest pains. Ocular (eye) involvement, which is very common, can cause blurred vision, loss of acuity (how well you see), decreased tearing, or even blindness. Skin involvement can produce tender, red bumps, plaques, rashes or nodules. Most of the time, the disease is found in patients with no symptoms but who have an abnormal chest x-ray. Generally, Sarcoidosis does not prevent successful pregnancy or delivery.

How do you test for it? Testing for Sarcoidosis usually begins with plain chest x-ray. Sarcoidosis can affect the lymph glands in the central area of the chest (usually both sides and significantly swollen) and/or cause reticulonodular  infiltrates (lines and small nodules) in the lungs. It can also go on to cause scarring of the lungs. The x-ray findings are not specific to Sarcoidosis, and can be seen in other conditions. Other testing includes chest CT scanning, pulmonary function testing (breathing tests), blood testing (complete blood count, serum calcium, serum chemistries, liver function tests, and thyroid function tests) and urine sampling (urine calcium). Sometimes, your doctor might obtain Angiotensin Converting Enzyme (ACE) levels, which may be abnormally high with Sarcoidosis and improve with treatment. This test is not specific to Sarcoidosis, however. An electrocardiogram (EKG) should be done once you have been diagnosed with Sarcoidosis. Holter (heart rhythm) monitoring might be done if arrhythmia is suspected. Eye examination (by an ophthalmologist) should be done to look for involvement of the eye. Sometimes a Gallium scan is done to look for generalized areas of inflammation, but the results are not specific to Sarcoidosis. Ultimately, your doctor will consider obtaining  tissue biopsies to help confirm or exclude the diagnosis. This may be accomplished through bronchoscopy, lymph node biopsy, skin biopsy, or biopsy of other affected organ. Your doctor will also do tests to exclude other conditions, such as tuberculosis, fungal infection, cancer and others. Many of these tests may be repeated during follow-up visits.

How is it treated? Treatment of Sarcoidosis depends upon the symptoms and organ(s) involved. Up to 2/3 of cases do not require any treatment (spontaneous remission). Corticosteroid, most commonly prednisone, has been the treatment standard for decades. The usual dose is 20-40 mg daily, with re-evaluation after 1-3 months. Some do not respond to steroids, however. Unfortunately, corticosteroids have many toxicities and adverse side effects. Severe symptoms are often treated with prednisone plus steroid-sparing agents, such as methotrexate, azothiaprine or cyclophosphamide. Once stabilized, your doctor will typically monitor you every 3-6 months for the first two years.

What is the prognosis? The prognosis for Sarcoidosis is generally good- up to 40% of cases resolved or cured within 6-12 months and more than 85% within 2 years. Relapses occur in only a small percentage of cases.  Only about 10-20%  have permanent sequelae (lung or other location). The overall mortality rate is 1-5%, usually from severe lung damage, central nervous system involvement, or heart involvement.

Where can I find more information?

American Thoracic Society: 1999 Statement on Sarcoidosis
National Heart, Lung and Blood Institute
American Lung Association
New England Journal of Medicine