Sarcoidosis is a rare disease that causes body cells to form into clumps, called granulomas, in the organs of the body (often the lungs and skin).
Typical symptoms are tender, red bumps on the skin, shortness of breath and a persistent cough. However, every person is affected differently and symptoms often depend on which organs are affected.
There's no cure for sarcoidosis, but for most people the disease will go away without treatment after a few years. Usually, symptoms are not crippling and do not affect everyday life (see Symptoms of sarcoidosis, below).
Sarcoidosis affects about 19 people in every 100,000 in the UK.
This page explains:
It's impossible to predict how sarcoidosis will affect a person, as symptoms can vary widely depending on which organs are affected (it can affect any organ).
For most people, sarcoidosis is short-lived: symptoms last a few years, then clear and never return. This is known as acute sarcoidosis.
Some people do not have any symptoms at all, and the disease is diagnosed after an X-ray carried out for another reason.
But a few people find that their symptoms appear gradually and get worse over time, to the point where they become severely affected. Lots of granulomas may form in an organ and prevent it from working properly. This form of the disease is known as chronic sarcoidosis.
Sarcoidosis usually starts in the lungs, skin and/or lymph nodes (glands). Typical symptoms are listed below. Someone with sarcoidosis will probably only have a few of these.
Sarcoidosis most commonly affects the lungs. This form of the disease is known as pulmonary sarcoidosis. The two main symptoms are:
For some people, the breathlessness and cough gradually get worse over time. This is a sign that the condition is chronic: it will affect you for a long time and symptoms may become severe.
Sarcoidosis commonly affects the skin, causing:
You may also have any of the following symptoms, if other organs are affected:
Normally, the body's immune system fights off any bacteria or viruses that infect the body by releasing white blood cells into the blood to isolate and destroy the germs. This results in inflammation (swelling and redness) of the body tissues in that area. The immune system responds like this to anything in the blood it doesn't recognise, and dies down when the infection has been cleared.
It is thought that sarcoidosis happens because the immune system has gone into 'overdrive'. The body starts to attack its own tissues and organs by sending out white blood cells, and this causes granulomas to form in the organs. Areas of the body then become inflamed, leading to symptoms such as tender, sore patches on the skin, and this inflammation does not die down.
There are many similar diseases, such as rheumatoid arthritis and lupus, that are caused by the body attacking its own tissues. These are collectively known as autoimmune diseases.
It is not known why the immune system behaves like this, but research is being carried out to see what triggers sarcoidosis ([search clinical trials for sarcoidosis]).
It's possible that something in the enviroment triggers the disease in people who are already genetically susceptible to the disease.
Sarcoidosis can occasionally occur in more than one family member, but there's no evidence that it can be passed from parents to children, nor is the disease infectious (it cannot be passed from person to person).
Sarcoidosis can affect people of any age, but usually starts in young adults aged between 20 and 40. It is rare in childhood.
For some reason, pulmonary sarcoidosis (which affects the lungs) is more common in African Americans and African-Caribbeans.
Many people with sarcoidosis do not need treatment as the disease often goes away on its own with time (usually a couple of years). Often, simple lifestyle changes and over-the-counter painkillers (such as paracetamol or ibuprofen) are all that is needed to control any flare-ups. See Living with sarcoidosis for lifestyle advice.
Doctors will monitor your disease to check if it's getting any better or worse. This can be done via regular X-rays, breathing tests and blood tests.
If medication is necessary, your doctor will probably try you on [prednisolone] steroid tablets. This is the most effective medication for sarcoidosis, helping to keep the inflammation under control.
However, if taken in high doses, steroid medication can cause unpleasant side effects such as weight gain and mood swings. If it is continued for a long time, additional side effects such as thinning of the bones and skin may occur.
Therefore, steroid medication should only be used when really necessary. If your symptoms are severe, you may be given a high dose of steroid medication for a short period of time and switch to a low dose for the months that follow. Your condition will be monitored during this time, to see how well the treatment is working.
Steroid treatment aims to relieve symptoms by reducing inflammation and damage to organs and possibly by preventing scarring.
Sometimes, steroids are not enough. Patients who are severely affected with chronic sarcoidosis may also need immunosuppressants, such as [infliximab], to weaken the body's immune system response.
The Sarcoidosis Charity UK recommends the following lifestyle measures to encourage the body to fight off sarcoidosis:
Sarcoidosis can reduce a woman's chance of becoming pregnant, but many women with the disease have given birth to healthy babies while on treatment.
Important: Our website provides useful information but is not a substitute for medical advice. You should always seek the advice of your doctor when making decisions about your health.