Sarcoidosis is a condition where tiny lumps (nodules), known as granulomas, develop at various sites within your body, due to inflammation. It most commonly affects the lungs. However, it can affect almost any part of the body. The exact cause is not known. In many people, sarcoidosis goes away without any treatment. However, in some people, it can become a serious long-term condition, which requires treatment.
What is sarcoidosis?
Sarcoidosis is a condition where tiny lumps (nodules), known as granulomas, develop at various sites within your body, due to inflammation. These granulomas are made up of cells involved in inflammation.
Sarcoidosis most commonly affects the lungs and lymph glands in the chest area (pulmonary sarcoidosis). However, it can affect almost any part of your body, including your eyes, skin, heart, liver, kidneys, salivary glands, muscles, nose, sinuses, brain and nerves. If lots of granulomas form in a part (or organ) of your body, this can start to affect how that part of your body works and functions. So, it is the presence of the granulomas formed in response to inflammation that causes the symptoms of sarcoidosis in the various parts of your body.
What causes sarcoidosis?
The exact cause of sarcoidosis is not known. However, it does seem to run in some families so it is likely that some people have a genetic tendency (susceptibility) to develop sarcoidosis. It has been suggested that something such as an infection or another 'agent' found in the environment may trigger sarcoidosis in someone who is genetically susceptible to it. So far, no definite infection or agent acting as this trigger has been identified.
How common is sarcoidosis?
Sarcoidosis is rare. Every year in the UK, around 3,000 people are diagnosed with sarcoidosis for the first time. It is most commonly first diagnosed between the ages of 20-40 years. However, sarcoidosis can affect younger or older people. Sarcoidosis seems to be more common in Scandinavian people as well as African-Americans and African-Caribbeans.
Which parts of the body are affected in sarcoidosis?
Sarcoidosis can affect almost any part of your body. It can also affect more than one part of your body at the same time:
- The lungs and the lymph glands in the chest area are most commonly involved in sarcoidosis. They are affected in about 9 in 10 people with sarcoidosis.
- The skin is affected in about 1 in 4 people with sarcoidosis.
- The lymph glands elsewhere in the body are affected in about 1 in 6 people with sarcoidosis.
- The eyes are affected in about 1 in 8 people with sarcoidosis.
- The nerves and nervous system are affected in about 1 in 20 people with sarcoidosis.
- The heart is affected in about 1 in 50 people with sarcoidosis.
- Sarcoidosis can also affect other parts of the body, including bones, joints, muscles, the liver, the spleen, the kidneys, and the gut.
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How does sarcoidosis develop and progress?
You may not know that you have sarcoidosis. It may be diagnosed when you have a chest X-ray for another reason. Up to half of people with sarcoidosis do not know that they have it. They have no symptoms.
The symptoms may come on quite quickly, over a couple of weeks or so. Some doctors call this acute sarcoidosis. Generally, acute sarcoidosis has a good outlook and tends to go away of its own accord without treatment. Löfgren's syndrome is a type of acute sarcoidosis. It is a combination of erythema nodosum (see below) with swollen or enlarged lymph glands seen on your chest X-ray, inflammation in your eye (uveitis) and joint pains.
In other people with sarcoidosis, symptoms come on more slowly over a few months or so. Some doctors call this chronic sarcoidosis. Symptoms can become worse over time and often treatment is needed.
What are the symptoms of sarcoidosis?
The symptoms can vary from person to person. This is because sarcoidosis can affect so many different parts of the body. Just one part of your body may be affected by sarcoidosis. Or, more than one part of your body may be affected. Some of the various parts of your body that can be affected and their associated symptoms include the following
You may notice shortness of breath (particularly on exertion), cough, wheezing, chest pain or (rarely) you may cough up blood (haemoptysis).
Erythema nodosum is a condition that causes red rounded lumps (nodules), most commonly on your shins. This may develop at the start of sarcoidosis and is the most common skin rash in sarcoidosis. See the separate leaflet called Erythema Nodosum for more details. Other skin problems that may occur include a purplish, raised rash on your nose, cheeks, chin and ears. This rash is called lupus pernio. Some people with sarcoidosis may develop small nodules just under the surface of their skin.
These may be swollen. See the separate leaflet called Swollen Lymph Glands for more details. You may notice lumps under the arms, in your neck, or in your groins. Doctors may also notice swollen glands in your chest area when they look at your chest X-ray.
Sarcoidosis can cause a type of inflammation within your eyes, called uveitis. In this condition the eyes become red and painful. It can also affect vision. See the separate leaflet called Uveitis for more details. You should see a doctor straightaway if you have sarcoidosis and notice any eye symptoms. Your doctor may suggest an examination of your eyes when you are first diagnosed with sarcoidosis, to look for any eye problems.
Sarcoidosis can affect your heartbeat by making it slower or irregular. Damage to your lungs, caused by sarcoidosis, may also cause changes in the right side of your heart and it can become enlarged. This is known as cor pulmonale and can lead to heart failure if left untreated. Your heart can also become generally enlarged in sarcoidosis, known as cardiomyopathy. This means that your heart cannot beat as strongly or effectively and you can become breathless. Cardiomyopathy can also lead to heart failure.
Your nervous system may be affected in a number of ways in sarcoidosis. For example, the nerves of your face, or your head, or your arms and legs may become affected. This may lead to problems with swallowing, drooping of your face or eyesight or hearing problems. Or you may notice numbness and pins and needles in your face, arms or legs. Sarcoidosis can also cause a type of meningitis. It can (rarely) lead to fits (convulsions) or a stroke.
Sarcoidosis may affect your kidneys, causing kidney stones because of high levels of calcium in your blood.
Liver and spleen
These organs may become enlarged in sarcoidosis. This can (rarely) cause problems with your blood clotting or can lead to anaemia.
Bones, joints and muscles
You may experience joint pains if you have sarcoidosis. Cysts can (rarely) develop in your bones. Inflammation of your muscles is also possible.
General symptoms may also develop which include high temperature (fever), loss of appetite and loss of weight. Fatigue can be a big problem for people with sarcoidosis. Some people may also become quite depressed.
How is sarcoidosis diagnosed?
Initial tests by your doctor
When diagnosing sarcoidosis, your doctor may ask you a number of questions if they suspect that you have sarcoidosis. This is to look for any symptoms that you may have and to see which parts of your body sarcoidosis could be affecting. Depending on your symptoms, your doctor may also suggest that they examine you. For example, they may suggest that they listen to your chest, carry out an examination of your lymph glands, examine your skin, etc.
Your doctor may then suggest some tests. Some of these tests may depend on which part of your body is affected. Tests may include:
- Blood tests - your doctor may suggest some blood tests to look for signs of inflammation. They may check the level of calcium in your blood, as this can be raised in sarcoidosis. They may also check your kidney and liver function and check for a lack of iron in the body (anaemia). Some doctors also suggest a blood test to check the levels of a protein (an enzyme) in your blood, known as angiotensin-converting enzyme (ACE). The levels of this protein are raised in some people with sarcoidosis. However, its usefulness in helping to diagnose sarcoidosis is thought to be limited.
- Chest X-ray - if your doctor suspects that your lungs may be affected by sarcoidosis, they will usually arrange a chest X-ray.
- Spirometry - your doctor may suggest a special test of your lungs, called spirometry. A spirometer is a device which measures the amount of air that you can blow out. See the separate leaflet called Spirometry for more details.
- Heart tracing (electrocardiogram, or ECG) - your doctor may arrange an ECG. This records the electrical activity of your heart and shows if there are any problems with this due to sarcoidosis that has affected your heart. See the separate leaflet called Electrocardiogram (ECG) for more details.
- Dipstick test of your urine - a special testing strip is dipped into your urine sample to look for any signs of blood vessel or kidney problems due to sarcoidosis.
Referral to a specialist
If your doctor suspects sarcoidosis, after some initial tests (above), they will usually refer you to a specialist to confirm the diagnosis. The specialist will also provide advice about how best to treat you. The specialist may suggest some other tests to help confirm the diagnosis and to see which parts of your body sarcoidosis is affecting. For example:
- A biopsy - in order to make a definite diagnosis of sarcoidosis, in most cases, a small sample of tissue (a biopsy) needs to be taken from one of the areas of inflammation (called granulomas). If your lungs are a problem, a bronchoscopy is usually done. A small telescope is passed via your nose, down your windpipe (trachea) and into your lungs. A sample of lung tissue is taken and sent to the laboratory. The inflammation of sarcoidosis has a typical appearance when it is examined under a microscope. A biopsy may also be taken from other areas if sarcoidosis is suspected there - for example, your skin, lymph glands, etc. Note: not everyone with sarcoidosis needs a biopsy. For example, if you have the typical symptoms of Löfgren's syndrome, you may not need a biopsy to confirm the diagnosis.
- CT or MRI scans - if your lungs are thought to be affected, a specialist may suggest a CT scan to allow a more detailed look at your lungs. An MRI scan of your heart or your brain may be suggested if sarcoidosis is thought to be affecting your heart or your nervous system.
- Echocardiogram - you may be referred for an ultrasound scan of your heart (an echocardiogram). This can show if your heart is enlarged or affected by sarcoidosis. Other investigations to look at your heart may also be suggested.
- More detailed lung function tests - other tests to look at how your lungs are working may be suggested. Lung function tests may also be used to look to see if your sarcoidosis is worsening or if it is responding to treatment.
- Tests to look for eye involvement - you may be referred for a detailed examination of your eyes by an eye specialist, even if you do not have any specific eye symptoms. This is because sarcoidosis involving the eyes can seriously affect your vision if it is not treated quickly. The examination will usually involve the specialist using a special microscope (a slit lamp) to examine your eyes.
What is the treatment for sarcoidosis?
More than three quarters of people with sarcoidosis do not need any treatment because their symptoms are not severe. However, sometimes simple painkillers such as paracetamol or non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, may help to ease symptoms. For example, they may help to ease pain from the rounded lumps (nodules) of erythema nodosum, or joint pains.
If treatment is needed for sarcoidosis, the aim of treatment is to reduce the inflammation and therefore the symptoms that it causes. Treatments for sarcoidosis include:
The main treatment for sarcoidosis is usually with steroid tablets. The steroids help to reduce inflammation. Prednisolone is usually used and generally needs to be taken daily at first. Treatment with steroid tablets is often needed for at least 6-24 months. Over this time, the dose of the steroid may be gradually reduced. You are more likely to need treatment with steroid tablets if sarcoidosis is affecting your nervous system, heart or eyes, or if you have high calcium levels in your blood, or severe breathing/lung symptoms. Steroid drops or ointments are sometimes used for sarcoidosis affecting the eyes.
Sometimes, steroid tablets may not be effective or may cause side-effects. Side-effects can include:
- An increased risk of infection.
- Thinning of the skin.
- 'Thinning' of the bones (osteoporosis).
- Difficulty sleeping and mood changes.
- Easy bruising.
- Weight gain.
- High blood pressure.
- An increased risk of developing diabetes.
Other sarcoidosis treatments with medicines
If steroid tablets are causing side-effects, or are ineffective, there are some other medicines that can be used as alternatives. These are broadly known as cytotoxic or immunosuppressive medicines.
Cytotoxic medicines work by killing some cells thought to be harmful to the body. Immunosuppressive medicines damp down the body's own immune system. In some illnesses, the immune system can work against the body.
Some of these medicines may be used alone (if steroids are not working), or they may be used in combination with steroids to reduce the dose of steroid needed. Each of the medicines has different possible side-effects. Some side-effects can be serious. Serious side-effects are rare but include damage to the liver and blood-producing cells. Therefore, it is usual to have regular tests, usually blood tests, whilst you take some of these medicines. The aim is that the tests look for possible side-effects before they become serious. You should ask your specialist to discuss in detail the side-effects of any medication that you are prescribed.
Surgery and non-medicinal treatment
Very rarely, sarcoidosis can cause severe scarring to the lungs. One of the options for treatment if this occurs is lung transplantation. Heart transplantation has also been used in rare cases where sarcoidosis severely affects the heart. Occasionally, people with sarcoidosis that is affecting the heart may need a pacemaker to help control the rhythm of the heart.
Will I need any follow-up or monitoring?
Generally, if you have sarcoidosis, you will be seen regularly by a specialist in an outpatient clinic. The specialist that you see will depend on which area of the body the sarcoidosis affects. For example, it is likely that you will see a lung (respiratory) specialist if the sarcoidosis affects your lungs and an eye (ophthalmology) specialist if it affects your eyes. You may need to see more than one specialist.
At each follow-up appointment the specialist may ask you questions about any symptoms that you have; they may arrange a chest X-ray and some lung function tests. They may arrange examination of your eyes. They may also suggest other tests, depending on your symptoms and which part of your body is affected.
If sarcoidosis affects your lungs then you should have an influenza immunisation each year.
What is the outlook (prognosis)?
Many people with sarcoidosis do not need any specific treatment. Their sarcoidosis will get better of its own accord over the following two to five years. However, for some people with sarcoidosis, it becomes persistent (chronic) and may require treatment. Someone with sarcoidosis can (rarely) be severely affected and may die. This is usually due to severe involvement of the lungs, leading to respiratory failure.
The outlook tends to be not as good if sarcoidosis affects areas of your body outside your lungs, particularly if it affects your heart or your nerves. People who develop sarcoidosis quickly, over a few weeks, tend to have a better outlook. So do those who develop erythema nodosum, or those who just have swollen lymph glands seen on their chest X-ray and no real breathing or chest symptoms.
Further reading and references
Seve P, Pacheco Y, Durupt F, et al; Sarcoidosis: A Clinical Overview from Symptoms to Diagnosis. Cells. 2021 Mar 3110(4). pii: cells10040766. doi: 10.3390/cells10040766.
Papanikolaou IC, Antonakis E, Pandi A; State-of-the-Art Treatments for Sarcoidosis. Methodist Debakey Cardiovasc J. 2022 Mar 1418(2):94-105. doi: 10.14797/mdcvj.1068. eCollection 2022.
Gerke AK; Treatment of Sarcoidosis: A Multidisciplinary Approach. Front Immunol. 2020 Nov 1911:545413. doi: 10.3389/fimmu.2020.545413. eCollection 2020.
Trivieri MG, Spagnolo P, Birnie D, et al; Challenges in Cardiac and Pulmonary Sarcoidosis: JACC State-of-the-Art Review. J Am Coll Cardiol. 2020 Oct 2076(16):1878-1901. doi: 10.1016/j.jacc.2020.08.042.
Soto-Gomez N, Peters JI, Nambiar AM; Diagnosis and Management of Sarcoidosis. Am Fam Physician. 2016 May 1593(10):840-8.