What is sarcoidosis?
Sarcoidosis, sometimes known as sarcoid, is an inflammatory condition which can affect various parts of the body, but most commonly affects the lungs. Sarcoidosis causes cells to group together to form granulomas, which most commonly develop in the lungs. They can also affect the liver, spleen, nose, sinuses, eyes, skin, lymph nodes and the heart.
Sarcoidosis can affect people of all ages but it is most common in young adults, with children rarely affected by the condition. It is estimated that 19 people in every 100,000 in the UK are affected by sarcoidosis.
In many cases, sarcoidosis is a mild condition, which may go away without treatment. However, in rare cases, sarcoidosis can be serious and affect the function of important organs, but it is estimated that life expectancy is only shortened in 2% to 5% of cases.
What causes sarcoidosis?
The cause of sarcoidosis is unknown, though there is a link with the immune system. Inflammation is one of the body’s ways of dealing with illness or injury and in people with sarcoidosis it is believed that the immune system is overactive. It is likely that sarcoidosis is triggered by an infection, which causes the immune system to act abnormally.
There is some evidence to suggest that family history can be a risk factor, but sarcoidosis is not infectious and cannot be passed from one person to another. Research into the causes of sarcoidosis is ongoing.
What are the symptoms of sarcoidosis?
In some cases, symptoms do not develop and some people have sarcoidosis without even knowing it. Often the condition is diagnosed as a result of an abnormal chest X-ray, which was ordered to check for another condition. Often the symptoms are mild, but they can be more serious. Symptoms tend to vary according to the part of the body affected.
Possible symptoms include:
- Blurred vision.
- Breathing difficulties.
- A dry cough.
- Tiredness and generally feeling unwell.
- Joint pain.
- Swollen lymph nodes (glands), which may be tender to touch.
- Red eyes.
- The development of small, red, tender lumps on the shins.
Sarcoidosis can come on quickly (acute) or develop gradually (chronic). Acute sarcoidosis often causes the lymph nodes to swell, joint pain, fever and the development of rashes, while symptoms of chronic sarcoidosis develop slowly and usually include breathing difficulties, which get worse as the condition progresses.
How is sarcoidosis diagnosed?
A number of tests will be carried out to reach a firm diagnosis. However, it may not be possible to confirm a diagnosis with the results of a single test, but doctors can be fairly sure of a diagnosis after a chest X-ray. Other tests, including a biopsy sample and a CT scan, will also be conducted. The biopsy sample is taken from the affected organ and the sample is then studied under a microscope to detect granulomas.
Once sarcoidosis has been diagnosed, other tests may be carried out to see how the condition is affecting the organs. Blood and urine tests may be conducted to check the calcium levels, a 24 hour ECG will check for damage to the heart and breathing tests (known as lung function tests) will be carried out to determine if the lungs are affected.
Treatment for sarcoidosis
At the moment there is no cure for sarcoidosis, however, many people live a normal life without treatment and research is ongoing. Often, doctors adopt a policy of watchful waiting because many patients do not require treatment. This means that they will monitor the patient’s condition and only recommend treatment if they develop symptoms or their condition becomes more advanced. The primary aims of treatment are to prevent damage caused by inflammation, improve quality of life and stop the progression of the condition.
Treatment may be required if an individual develops symptoms or tests show that the condition is progressing. The type of treatment used will usually depend on the organ affected but steroids are the most common treatment. In most cases, where treatment is required, taking steroids is sufficient to prevent the condition from getting worse. In most cases, a short course of high dose steroids is given, followed by a longer course of low dose steroids, as taking high doses of steroids for a long time can cause side-effects. Steroids are usually taken in tablet form but there are other forms available, which may be more suitable for certain organs, including steroid eye drops, which can be put directly into the eyes.
In rare cases, steroids may not be enough to prevent symptoms and stop the condition progressing. If this is the case, immunosuppressants may be used, which are drugs used to suppress the activity of the immune system to help reduce the potency of the inflammatory response.
What is the outlook for sarcoidosis?
Sarcoidosis affects people in different ways but for most people the outlook is very positive, with many people living a normal life and some people never experiencing any symptoms. 90% of people with acute sarcoidosis do not require treatment but treatment is more commonly required for chronic sarcoidosis, as symptoms tend to flare up now and again. In rare cases, chronic sarcoidosis gets worse over a period of time and can cause significant damage to the organs. Also, in very rare cases, heart or lung sarcoidosis can be fatal.