Sarcoidosis - or sarcoid - is a condition in which cells involved in inflammation clump together to form small lumps called granulomas. These granulomas can affect any part of the body, but most commonly affect the lungs. They can also affect the skin, lymph nodes, heart, brain, liver, spleen, muscles, nose, sinuses and eyes. When lots of granulomas develop in one part of the body they begin to affect how well that organ works.
Sarcoidosis can occur at any age but is most frequent in young adults. It is rare that children get sarcoidosis. The condition affects about 19 people in every 100,000 in the UK.
The cause or causes of sarcoidosis are unknown. Research is still being carried out to find out more about what triggers the disease. Researchers think it may be caused by something in the environment that affects people who have no defence against the disease, probably because of their genes. Occasionally it occurs in more than one member of the family, but there is no evidence that it is infectious and passes from one person to another.
The symptoms you have will depend on which organs are affected by the condition. Symptoms can include:
- a dry cough
- tiredness, fatigue or feeling ill
- sore eyes
- tender, painful red lumps on the shins
- swollen lymph glands in the face, neck orarmpits - these can be felt as sore lumps
- rashes - most commonly on the upper body
- joint pains
Acute (short-term) sarcoidosis occurs suddenly, with enlarged lymph glands, fevers, fatigue, lumps or rashes on the legs and joint pains. Chronic (long-term) sarcoidosis comes on more gradually and lasts longer. It produces increasing breathlessness and may affect other organs.
In some cases there are no symptoms and sarcoidosis will only be picked up because of unusual results on a chest X-ray which is done for another reason.
Different tests will be done to find out if you have sarcoidosis depending on the symptoms you’re experiencing. However, in most cases, doctors can tell a patient has sarcoidosis from looking at a chest X-ray or CT scan of the lungs.
In many cases a tissue sample (biopsy) is taken from the affected organ. The sample is then looked at under a microscope to see if there are typical sarcoidosis lumps (granulomas). This is the best way to diagnose the illness, as it rules out other diseases that may cause similar symptoms (for example tuberculosis). The biopsy is sometimes taken using a bronchoscope - a small telescope which is passed into the lungs, via the nose and windpipe.
Once sarcoidosis has been diagnosed, other tests help to reveal how various organs are affected. Blood calcium levels may be raised, so blood tests and urine tests may be done. Also breathing tests will find out how much the lungs are affected and an ECG (an electrical tracing of the heart) reveals if the heart has been affected.
Since only a minority of people with sarcoidosis require specific treatment, it is common for doctors to observe your symptoms and test results for a few months in case your sarcoidosis becomes inactive on its own. It is usual to repeat chest X-rays, breathing and blood tests regularly to monitor the condition. If your symptoms continue and tests show the condition is getting worse, then treatment may be needed.
The aim of treatment for sarcoidosis is both to relieve symptoms and to prevent scarring and damage to major organs. Steroids are an effective way of suppressing sarcoidosis and for many people will be the only treatment needed. Steroids can be given directly to an affected area - for example. eye drops for eye symptoms. More usually, they are given as a course of tablets.
Although steroids are generally safe, they have side-effects if used in high doses over a long period of time. For this reason treatment is usually a high dose of tablets over a short period of time, followed by a safer, low dose over a much longer period. For more information about the side effects of steroids please refer to our booklet on Idiopathic Pulmonary Fibrosis, which contains a section about steroids.
If steroids are stopped too soon sarcoidosis may become active again and cause more scarring. It is therefore usually necessary to continue treatment for up to 12 months before stopping. Although usually only one course of steroids is needed, occasionally the sarcoidosis may become active again and a second course of steroids is required. Only a small number of people with sarcoidosis need long-term treatment with steroids to stay healthy.
For very few people, steroids are not enough to prevent sarcoidosis getting worse. In these cases other treatments which suppress the body’s immune defence system (immunosuppressants) can be used. A number of new medicines are currently undergoing trials and may be available as treatments for sarcoidosis in the future.