Sarcoidosis

Sarcoidosis is a multi-system disease of unknown etiology characterized by the formation of granulomas in various organs. It affects people of all ethnic backgrounds and occurs at any time of life but is more frequent in African Americans and Scandinavians and in adults between 30 and 50 years of age. Sarcoidosis can affect any organ with a frequency varying according to ethnicity, sex and age. Intrathoracic involvement occurs in 90% of patients with symmetrical bilateral hilar adenopathy and/or diffuse lung micronodules, mainly along the lymphatic structures which are the most affected system. Among extrapulmonary manifestations, skin lesions, uveitis, liver or splenic involvement, peripheral and abdominal lymphadenopathy and peripheral arthritis are the most frequent with a prevalence of 25-50%. Finally, cardiac and neurological manifestations which can be the initial manifestation of sarcoidosis, as can be bilateral parotitis, nasosinusal or laryngeal signs, hypercalcemia and renal dysfunction, affect less than 10% of patients. The diagnosis is not standardized but is based on three major criteria: a compatible clinical and/or radiological presentation, the histological evidence of non-necrotizing granulomatous inflammation in one or more tissues and the exclusion of alternative causes of granulomatous disease. Certain clinical features are considered to be highly specific of the disease (e.g., Löfgren's syndrome, lupus pernio, Heerfordt's syndrome) and do not require histological confirmation. New diagnostic guidelines were recently published. Specific clinical criteria have been developed for the diagnosis of cardiac, neurological and ocular sarcoidosis. This article focuses on the clinical presentation and the common differentials that need to be considered when appropriate.

Signs and symptoms of sarcoidosis vary depending on which organs are affected. Sarcoidosis sometimes develops gradually and produces symptoms that last for years. Other times, symptoms appear suddenly and then disappear just as quickly. Many people with sarcoidosis have no symptoms, so the disease may be discovered only when a chest X-ray is done for another reason.

General symptoms

Sarcoidosis can begin with these signs and symptoms:

Fatigue

Swollen lymph nodes

Weight loss

Pain and swelling in joints, such as the ankles

Lung symptoms

Sarcoidosis most often affects the lungs and may cause lung problems, such as:

Persistent dry cough

Shortness of breath

Wheezing

Chest pain

Skin symptoms

Sarcoidosis may cause skin problems, which may include:

A rash of red or reddish-purple bumps, usually located on the shins or ankles, which may be warm and tender to the touch

Disfiguring sores (lesions) on the nose, cheeks and ears

Areas of skin that are darker or lighter in color

Growths under the skin (nodules), particularly around scars or tattoos

Eye symptoms

Sarcoidosis can affect the eyes without causing any symptoms, so it's important to have your eyes checked regularly. When eye signs and symptoms do occur, they may include:

Blurred vision

Eye pain

Burning, itching or dry eyes

Severe redness

Sensitivity to light

Heart symptoms

Cardiac sarcoidosis: A heart under attack

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Signs and symptoms related to cardiac sarcoidosis may include:

Chest pain

Shortness of breath (dyspnea)

Fainting (syncope)

Fatigue

Irregular heartbeats (arrhythmias)

Rapid or fluttering heart beat (palpitations)

Swelling caused by excess fluid (edema)

The exact cause of sarcoidosis is not known. The disease can appear suddenly and then disappear, or it can develop gradually and produce symptoms that come and go for a lifetime.

Researchers believe that the disease is caused by an abnormal immune response. (The body’s defense system does not react as it should to a foreign substance "intruder.") In a healthy person, inflammation occurs as the cells of the body’s immune system come together to fight the intruder at an organ or tissue site. In a person with sarcoidosis, however, cells that come to fight end up clumping together into small lumps called granulomas.

It’s still uncertain which foreign substance "triggers" the body’s abnormal response. Some researchers suggest that fungi, viruses, or bacteria are likely triggers. In fact, cases of sarcoidosis have occurred in groups of people who had close contact with each other, as well as in recipients of heart, lung and bone marrow transplants. But, so far, no data have been able to convincingly and consistently establish this "infectious" connection as the cause of the disease. However, some types of bacteria have recently emerged as possible candidates and continue to be closely studied.

While anyone can develop sarcoidosis, factors that may increase your risk include:

Age and sex. Sarcoidosis can occur at any age, but often occurs between the ages of 20 and 60 years. Women are slightly more likely to develop the disease.

Race. People of African descent and those of Northern European descent have a higher incidence of sarcoidosis. African-Americans are more likely to have involvement of other organs along with the lungs.

Family history. If someone in your family has had sarcoidosis, you're more likely to develop the disease.

Sometimes sarcoidosis causes long-term problems.

Lungs. Untreated pulmonary sarcoidosis can lead to permanent scarring in your lungs (pulmonary fibrosis), making it difficult to breathe and sometimes causing pulmonary hypertension.

Eyes. Inflammation can affect almost any part of your eye and may cause damage to the retina, which can eventually cause blindness. Rarely, sarcoidosis also can cause cataracts and glaucoma.

Kidneys. Sarcoidosis can affect how your body handles calcium, which can lead to kidney stones and reduce kidney function. Rarely, this can lead to kidney failure.

Heart. Cardiac sarcoidosis results in granulomas in your heart that can disrupt heart rhythm, blood flow and normal heart function. In rare instances, this may lead to death.

Nervous system. A small number of people with sarcoidosis develop problems related to the central nervous system when granulomas form in the brain and spinal cord. Inflammation in the facial nerves, for example, can cause facial paralysis.

There is no way to avoid getting sarcoidosis. If you are at higher risk for the disease, it may be better for you to avoid environmental substances that are known to trigger it. These could include insecticides, mold, or other substances.