What is sarcoidosis?
Sarcoidosis, or ‘sarcoid’, is a disease that can affect many parts of the body. It results in areas of inflammation that can result in pain and swelling.
Any part of the body can be affected, but the most commonly affected areas are the lungs, skin, eyes and lymph nodes. More rarely, the heart kidneys, liver and brain can be affected. One area alone may be affected, or many at once. Some people will need treatment, but for most a full recovery is possible, even without treatment.
What causes sarcoidosis?
Sarcoidosis is believed to be one of the autoimmune diseases where the body attacks itself. Why this happens isn’t clear, but infection often precedes the first signs of the disease.
Although it may occur at any age, young adults are far more likely to develop sarcoidosis. It sometimes runs in families and those of Afro-Caribbean descent are more likely to be affected.
Diagnosis of sarcoidosis isn’t always easy, as many other conditions cause similar symptoms. Often, it is only discovered when an x-ray of the chest reveals the characteristic swollen lymph nodes or shadowing in the lungs. Examining a sample of tissue taken from affected skin or lung under the microscope is an accurate way of confirming the diagnosis.
Since the lungs are commonly affected, tests to assess lung function are usually performed. Sarcoidosis can also cause the level of calcium in the blood to rise, which may also be measured.
What are the symptoms?
As with many diseases, sarcoidosis is often present without causing any symptoms. When symptoms do appear, however, they either do so abruptly (acute sarcoidosis) or gradually over a number of years (chronic sarcoidosis).
Sarcoidosis can result in:
- Blurred vision.
- Painful joints.
- General loss of wellbeing.
- Red and tender lumps usually appear on the shins (called erythema nodosum).
- Blurred vision and red eyes.
- Lymph nodes enlarge and are tender.
Over the years, chronic sarcoidosis may cause coughing and shortness of breath as the lungs become more and more inflamed, and their ability to function deteriorates. The eyes and shins may also be affected in the same way as in acute sarcoidosis.
How is sarcoid diagnosed?
Diagnosis of sarcoidosis isn’t always easy, as many other conditions cause similar symptoms. In order to confirm the diagnosis of sarcoidosis, doctors must take some time to explore and eliminate other possible diagnoses.
Often, sarcoidosis is only discovered when an x-ray of the chest reveals the characteristic swollen lymph nodes or shadowing in the lungs. Examining a sample of tissue taken from affected skin or lung under the microscope and finding the characteristic pattern of inflammatory cells (called a granuloma or granulomatat) is the gold standard to confirm diagnosis.
Investigations may involve one or more of the following tests to assess the activity of the sarcoid, the organs affected, and the best place from which to take a biopsy.
- Blood tests, including tests of serum ACE, calcium and tests of liver and kidney function.
- X-ray and CT (“CAT”) scan of your chest to identify the pattern of scarring in your lungs.
- Pulmonary function tests to measure breathing capacity.
- Biopsy of an affected organ or lymph-node which may include
- Lung cell sample by passing a small flexible telescope (a bronchoscope) down the breathing tubes in order to examine cells and look for signs of inflammation, together with
- EBUS (endobronchial ultrasound) to take a sample of the lymph-nodes in the chest safely using a very special bronchoscope so that there is no need for an operation.
Can sarcoid be treated or prevented?
Currently, there is no cure for sarcoidosis, but there are very efficient treatments. For the majority of those with the disorder – around eight out of every ten people, in fact – the condition resolves spontaneously after a few years and never comes back. For one in ten people, the disease slowly gets worse over time and, for 2% of patients, it can be very severe.
Relief from symptoms can be found with anti-inflammatory painkillers, and steroids can also prove extremely effective. When used to treat chronic sarcoidosis, steroids may need to be used at a low dose for many months, sometimes a year or more. During this time, regular blood and lung function tests and chest x-rays are performed to monitor how well the treatment is working. In more severe cases, immunosuppressive drugs such as methotrexate are used. Newer drugs, such as infliximab, may also be prescribed.
Living with sarcoidosis
Please consult your doctor before making changes to your lifestyle.
- Quit smoking to help increase oxygen levels in your blood and lower blood pressure and heart rate.
- Eat less saturated fat and more fruits and vegetables.
- Exercise to help keep your body working as efficiently as possible.
- Lose excess weight to help improve your breathing capacity.
- Avoid situations in which you might catch infections from others.
- Seek emotional support through family, friends, healthcare providers and support groups.
- Don’t over exert yourself and ensure you get enough rest.
- Make sure your immunisations are up to date.
- You may be asked to avoid calcium containing foods if your calcium is high.
- You may be asked to avoid excessive sunlight if your calcium is high.
- At UCL, we are carrying out studies into the immune systems of patients with sarcoid and comparing them with normal volunteers and patients with other diseases. This involves a simple blood test and the white blood cells are then examined more fully in the laboratory.
- Sarcoidosis runs in families and we are looking at genetic factors that may be important.
- Our current scans tell us if an organ has been damaged by sarcoidosis but not whether the disease is still active. We are investigating new scans that can pick up active sarcoid in places such as the heart, so that we can tailor drug treatments appropriately.
- EBUS is a very safe and painless way to examine the lymph nodes in the chest. We are investigating the best way to select patients in which EBUS will give a diagnosis.