Sarcoidosis: symptoms, causes, treatment and outlook

Sarcoidosis behaves unpredictably. The NHS says most people who get symptoms develop them suddenly, and that these usually clear within a few months or years and do not come back (acute sarcoidosis). Some people have no symptoms at all and the condition is found on an X-ray taken for another reason. A smaller group develop symptoms gradually that worsen over time, with so many granulomas forming in an organ that it cannot work properly, which is called chronic sarcoidosis.

In the lungs the main symptoms are shortness of breath and a persistent dry cough, with chest discomfort less common. Asthma + Lung UK adds wheezing and notes that around 8 in 10 people with sarcoidosis have fatigue. On the skin there can be tender bumps or patches, particularly on the lower legs and arms, which are reddish-brown or purple depending on skin colour. Other possible features listed by the NHS include swollen glands in the face, neck, armpits or groin, tiredness, painful joints, red or sore eyes, an abnormal heart rhythm, a blocked nose, bone pain, kidney stones and headache. Asthma + Lung UK also lists unexplained weight loss, fever and night sweats.

• Breathlessness, especially on exertion, and a dry cough that does not go away.

• Tender skin bumps, often on the lower legs.

• Swollen glands, painful joints, red or sore eyes.

• Marked tiredness that is out of proportion to activity.

In sarcoidosis, cells in the body join together to form tiny lumps of inflamed tissue called granulomas. Asthma + Lung UK explains that when there are lots of granulomas in one area, the inflammation can affect how well that part of the body works, and that granulomas are not always harmful. They are most often found in the lungs, skin and lymph nodes (glands). The NHS describes sarcoidosis as a rare condition and says the symptoms depend entirely on which organs are involved.

Many people do not need treatment, because sarcoidosis often goes away on its own. The NHS says simple lifestyle measures and over-the-counter painkillers such as paracetamol or ibuprofen are often all that is needed for flare-up pain, while doctors monitor the condition with X-rays, breathing tests and blood tests. Asthma + Lung UK says treatment may be needed if symptoms seriously affect quality of life or if the specialist thinks the lungs could be permanently damaged.

When treatment is recommended, steroid tablets are usually used, to relieve symptoms and to prevent organ damage by reducing inflammation and scarring. A higher dose may be given for a short time before switching to a low dose, and Asthma + Lung UK says the dose can be reduced gradually and that you may be able to stop after 6 to 12 months, or need longer if symptoms return. Steroids can cause side effects such as weight gain and mood swings at high doses and weakening of the bones with long-term use, so they are only used when necessary, and a doctor may advise calcium or vitamin D. Other immunosuppressants such as azathioprine, methotrexate or mycophenolate may be used if steroids are not enough or side effects are a concern.

Asthma + Lung UK says that after diagnosis you will have a review with the specialist team every 3 to 6 months for the first two years, and that people with chronic pulmonary sarcoidosis should have access to specialist respiratory nurses, with referrals for pulmonary rehabilitation or occupational therapy where helpful. Breathing techniques, energy pacing and, in some people with low oxygen levels, home oxygen therapy can also help.

The cause is not known. Researchers think it is linked to the immune system overreacting to an infection or to something breathed in from the environment. The NHS lists possible contributors including environmental exposures such as mould, soil, insecticides and silica, viral or bacterial infections, genetics, and the immune system attacking the body's own tissues. It is not infectious. Sarcoidosis can occasionally affect more than one family member, although the NHS says there is no evidence that it is inherited, while Asthma + Lung UK notes that around 1 in 10 people with the condition have a relative who also has it.

Asthma + Lung UK says sarcoidosis is uncommon in adults and very rare in children, affecting around 1 in every 10,000 adults and 1 in 100,000 children. It may start at any age, but the NHS says it usually starts in adults aged between 30 and 40, while Asthma + Lung UK gives a risk range of 20 to 50 years. Both sources say it is more common in women than men.

Risk may be higher for people who live or work around substances such as mould, soil, insecticides and silica, including some farmers and construction workers, for people with a family history or an identical twin with sarcoidosis, and for people who are African-American, African-Caribbean or Scandinavian. The NHS also says it affects people from all ethnic backgrounds.

Asthma + Lung UK says sarcoidosis can be difficult to diagnose because its symptoms are the same as those of many other conditions. Your GP will ask about symptoms, work and medical history and, if the lungs could be involved, refer you to a specialist. The tests vary from person to person. They can include spirometry (one forced breath in and out), a gas transfer test showing how much oxygen passes into the blood, blood tests, a chest X-ray, and a CT scan, which can check for signs of the condition and see how it is progressing.

A bronchoscopy, where a thin flexible tube with a camera is passed through the mouth into the airways, may be used to take small samples (a biopsy) that are examined under a microscope for granulomas. An endobronchial ultrasound (EBUS) bronchoscopy can reach areas that a standard bronchoscope cannot, and Asthma + Lung UK says it is more likely to give a clear diagnosis than a standard bronchoscopy. If other organs such as the skin, heart or eyes may be involved, the NHS says scans or examinations of those areas are usually arranged.

Outcomes vary widely. Asthma + Lung UK says many people fully recover within two to five years without treatment, while others develop chronic disease, and it states that around 1 in 4 people develop scarring (fibrosis) in the lungs or elsewhere in the body. The NHS says most people find their symptoms have disappeared within a few years of diagnosis, but for some the condition slowly gets worse and causes organ damage, for instance with increasing breathlessness.

The NHS suggests stopping smoking, eating a balanced diet, maintaining a healthy weight, reducing stress, exercising regularly and getting enough sleep. Support is available through Sarcoidosis UK, a charity that offers information and support groups. If you have breathlessness that is severe, you are struggling to breathe or symptoms are getting rapidly worse, Asthma + Lung UK says to call 999.

The NHS says sarcoidosis is not infectious, so it cannot be passed from person to person. Asthma + Lung UK says the same of pulmonary sarcoidosis.

The NHS says it can occasionally occur in more than one family member, but there is no evidence that the condition is inherited. Asthma + Lung UK notes that around 1 in 10 people with sarcoidosis also have someone else in their family with it.

Asthma + Lung UK says to call 999 if you are severely breathless, you are struggling to breathe or your symptoms are rapidly getting worse. If your symptoms are worse than usual but not an emergency, talk to your specialist team, or to your GP who can refer you if needed. It notes that flare-ups can happen when you are stressed or unwell, but also without a clear reason, and can last from a day to several months.

The NHS lists red or sore eyes, an abnormal heart rhythm and kidney stones among the possible symptoms when other organs are involved, and says scans or examinations of those areas are usually arranged. If you notice new symptoms like these, tell the team looking after you so that the right organ checks can be arranged.

The usual NHS route is GP assessment, chest imaging and blood tests, then referral to a respiratory or other specialist depending on the organs involved. Asthma + Lung UK says that after diagnosis you will have a review with the specialist team every 3 to 6 months for the first two years, and that you can be seen at your GP surgery if you do not need any treatment.

Because sarcoidosis can affect the eyes, heart and nervous system, review by more than one specialty is sometimes needed. Some people choose private respiratory care for assessment or a second opinion; if you do, ask how follow-up will be shared with your GP and NHS team.