Sarcoidosis is a disease characterized by the growth of tiny collections of inflammatory cells (granulomas) in any part of your body — most commonly the lungs and lymph nodes. But it can also affect the eyes, skin, heart and other organs.
The cause of sarcoidosis is unknown, but experts think it results from the body's immune system responding to an unknown substance. Some research suggests that infectious agents, chemicals, dust and a potential abnormal reaction to the body's own proteins (self-proteins) could be responsible for the formation of granulomas in people who are genetically predisposed.
There is no cure for sarcoidosis, but most people do very well with no treatment or only modest treatment. In some cases, sarcoidosis goes away on its own. However, sarcoidosis may last for years and may cause organ damage.
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.
Sarcoidosis can begin with these signs and symptoms:
- Swollen lymph nodes
- Weight loss
- Pain and swelling in joints, such as the ankles
Sarcoidosis most often affects the lungs and may cause lung problems, such as:
- Persistent dry cough
- Shortness of breath
- Chest pain
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
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
Signs and symptoms related to cardiac sarcoidosis may include:
- Chest pain
- Shortness of breath (dyspnea)
- Fainting (syncope)
- Irregular heartbeats (arrhythmias)
- Rapid or fluttering heart beat (palpitations)
- Swelling caused by excess fluid (edema)
Sarcoidosis can also affect calcium metabolism, the nervous system, the liver and spleen, muscles, bones and joints, the kidneys, lymph nodes, or any other organ.
When to see a doctor
See your doctor if you have signs and symptoms of sarcoidosis.
Doctors don't know the exact cause of sarcoidosis. Some people appear to have a genetic predisposition to develop the disease, which may be triggered by bacteria, viruses, dust or chemicals.
This triggers an overreaction of your immune system, and immune cells begin to collect in a pattern of inflammation called granulomas. As granulomas build up in an organ, the function of that organ can be affected.
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.