More about interstitial lung disease

When interstitial lung disease (ILD) is found in children it is called ChILD. This term covers a large group of rare lung diseases which all affect the interstitium (a network of tissue inside the lung).

• How are the lungs affected?

  ChILD can affect the lungs in many different ways, most commonly there is a thickening of the walls of the interstitium which makes it harder for the lungs to expand (inhale) or contract (exhale). The walls of the interstitium are where oxygen enters the body and carbon dioxide leaves.

  Thickening of the interstitium can lead to a decrease in oxygen which may make a child short of breath and to make up for this they will often breathe faster. This in turn can make them use up more energy, get tired more easily and be unable to exercise for as long when compared to their peers.

  With so much energy needed for breathing, children often do not gain weight and may even lose weight, even if they are eating well.

• Do we know the cause?

  Due to the range and rareness of these diseases, some causes have been found, but some have not.

  We do know that some forms of ChILD can be inherited, and your doctor could discuss whether it a genetic cause is known for your child’s condition

• Signs and symptoms

  Some of the main signs and symptoms are below but not every child with ChILD will have all these symptoms:

  • Shortness of breath
  • Rapid breathing
  • Difficult and heavy breathing
  • Getting tired more easily than their peers e.g. frequent stopping when walking, difficulty climbing stairs
  • Not gaining weight or losing weight (called failure to thrive)
  • Breathing noises e.g. rattles, crackles or wheezing
  • Persistent cough
  • Blue tinged lips because of low oxygen levels in the blood
  • Clubbed fingers (spoon shaped fingertips) and hourglass nails (rounding of the nails)

  Having these symptoms does not mean your child is affected with ChILD.

• How will it develop over time?

  In most cases, ChILD is a long-term disease and children may have a reduced lung function in adulthood, but this is not always the case.

  Children can learn to live with their disease and more often than not, can improve each year as their capacity to exercise increases.

  The uncertainty about what lies ahead for your child can be very difficult to deal with. Parents who have children with ChILD say it is helpful to think in small steps; to take comfort in all improvements and not to despair if there is a setback.

• What to do if you are concerned?

  If your child has the signs and symptoms outlined in the section above, then contact your doctor, explain your concerns and ask whether your child should be discussed with a specialised medical centre with experience in the evaluation and treatment of children with ChILD.

  Because these diseases are so rare, not many doctors will have knowledge or experience of dealing with children with ChILD.

Information about some of the more common ChILD conditions

This information is coming very soon - please check back!

There are over 200 different conditions under the ChILD umbrella. As with all rare conditions, it can take a long time to get a specific diagnosis. Information about some of the more common ChILD conditions are below:

• ABCA3

  ABCA3 and how the lungs work

  The lungs work by moving air in and out of the breathing tubes and connecting that air to blood vessels. The smallest unit of the lung at the end of all the breathing tubes is an alveolus. The alveolar wall consists of specialized cells (pneumocytes) and a very thin membrane which is surrounded by the smallest type of blood vessel, a capillary.

  The close proximity of the alveolus and capillary allows oxygen from the air in the alveolus to move into the blood stream, and carbon dioxide from the blood stream to move into the alveolus and be breathed out.

  Pneumocytes can be divided into type I and type II pneumocytes. Type II pneumocytes are responsible for the production and excretion of surfactant.

  Surfactant is a complex surface-active mixture consisting of different lipids and proteins which line the alveolar wall. The main function of surfactant is the reduction of surface tension to prevent collapse of the alveoli at the end of expiration. Surfactant has also anti-inflammatory and antimicrobial properties.

  In patients with ABCA3 mutation (change in the DNA) the production of surfactant as well as their excretion into the alveolar space is weakened. This can lead to a collapse of the alveoli which obstructs the transfer of oxygen into the blood stream and the transfer of carbon dioxide from the blood stream into the alveolus and is often accompanied by inflammation within the alveolar wall.

  Diagnosis

  The severity of the condition depends on the kind of mutation in the ABCA3 genes and other environmental factors, but most children develop symptoms during the first months of life. Problems with breathing and feeding are often present. Breathing often becomes worse over time, with low oxygen levels and marked increase work of breathing (tugging below and between the ribs).

  In hospital, children may be provided with oxygen, or when the problems get worse they may be given support by face mask ventilation or full ventilation by a breathing tube.

  Initially doctors may consider if there is an infection causing the problem but as time progresses and there is no improvement (or more typically worsening) the diagnosis of ABCA3 mutation will be considered.

  Diagnosis can only be confirmed or excluded by a genetic test.
  
  In some cases however, a lung biopsy may be considered, so that a piece of lung tissue can be looked at under a microscope.
  
  

  Treatment and outlook

  For some children, this condition will stabilise or improve under treatment with steroids, hydroxychloroquine and/or azithromycin.

  Lung transplant may be an option for very sick children who see no improvement under treatment.

  More than 50% of affected children do not survive their first year.

• Alveolar capillary dysplasia (ACD)

  Also known as alveolar capillary dysplasia with misaligned pulmonary veins or congenital alveolar dysplasia. Not to be confused with congenital acinar dysplasia.

  The main job of the lungs is to bring oxygen into your bloodstream - and to remove carbon dioxide. This process is called gas transfer, and takes place in tiny air sacs called alveoli that are surrounded by capillaries, the smallest type of blood vessel, which are at the end of the breathing tubes (bronchioles) in our lungs.

  Children with alveolar capillary dysplasia (ACD) are born with too few capillaries. They can breathe air in and out, but do not have enough capillaries to take the oxygen in and remove the carbon dioxide.

  Infants with ACD often have problems with breathing and feeding at birth or in the first few weeks of life. Their breathing issues often get worse quite quickly, with the child working very hard to breathe (tugging below and between the ribs) and having low oxygen levels. In hospital, children may be put on oxygen – which may be through face mask ventilation or full ventilation by a breathing tube.

  Diagnosis

  At first doctors may think that a child with ACD has an infection, but as time goes on and they do not improve – or get worse – a diagnosis of ACD might be considered.

  40-60% of infants with ACD have a gene called FOX-F1, and tests may be available for this gene.

  In most cases, a lung biopsy – where a piece of tissue is taken from the lungs and studied under a microscope – is needed to make the diagnosis.

  Children with ACD may also have issues with their blood vessels in other organs, such as the heart and gut.

  Treatment and outlook

  Unfortunately, there is no treatment for ACD. Lung transplant could be an option, but is technically extremely difficult in such young infants and has not been available to date. Most children with ACD do not survive their first year.

• Bronchiolitis obliterans (BO)

  Also known as obliterative bronchiolitis, or constrictive bronchiolitis obliterans. Not to be confused with bronchiolitis obliterans organising pneumonia (BOOP).

  There are many causes of bronchiolitis obliterans (BO), but children mostly get it after having an infection like adenovirus, respiratory syncytial virus (RSV), flu or mycoplasma pneumonia.

  Children that get BO are typically 1–5 years old, but it can occur at any age. They will get a bad chest infection – which at first seems typical, but lasts a long time and they may need support in intensive care.

  Even when they are generally covered from the infection, children with BO will still have fast breathing and low levels of oxygen in their blood. Healthcare professionals may also hear regular crackles when they listen to their chest with a stethoscope.

  Diagnosis

  BO is most often diagnosed based on a child’s symptoms together with a CT scan to check for damage to their airways.

  Treatment and outlook

  BO causes damage to the airways which cannot be repaired. The large airways become larger with floppy sides that are thicker than usual (called bronchiectasis). People with bronchiectasis are prone to infection and cannot clear mucus. The smaller airways (called bronchioles) become blocked (obliterated) – completely or partially – with scar tissue.

  Where the airway is partially blocked, air can get trapped, making that portion of the lung look too big (hyperinflated). Other areas of the lung that have not been affected can be squashed by the hyperinflated areas and so do not breathe as well as they would otherwise.

  Children with BO may need long-term support to help them with their breathing, such as extra oxygen and chest physiotherapy to help them clear their lungs. They can also be prone to chest infections.

  There is no known treatment to prevent BO.

• Hypersensitivity pneumonitis

  Information coming soon

• Neuroendocrine cell hyperplasia of infancy (NEHI)

  Also called chronic tachypnoea of infancy, or persistent tachypnoea of infancy (PTI)

  Young children with this condition usually have fast breathing (tachypnoea) and struggle to gain wait in their first few months of life. They may also have chest infections which need hospital treatment – and after which the levels of oxygen in their blood do not recover.

  Diagnosis

  Your child’s doctor may hear a fine crackling sound when listening to the child’s chest with a stethoscope.

  A computerised tomography (CT) scan of the chest can be used to help with a diagnosis, especially in children who have fast breathing and are having to work very hard to breathe (you may be able to see a tugging below and between the ribs).

  In some cases, a lung biopsy may be helpful to make a diagnosis.

  Treatment and outlook

  Children with NEHI usually get better over time, with most improvements in the first 2–3 years. There are no reports of death in children with NEHI.

  There is no specific treatment for NEHI, but children can be supported with oxygen therapy (usually delivered through the nose) and by increasing the number of calories in their diet to help them gain weight.

• Pulmonary alveolar proteinosis

  Information coming soon.

• Pulmonary interstitial glycogenesis (PIG) and heart defects

  This is a lung condition caused by pulmonary interstitial glycogenosis, also known as PIG.

  The lungs work by moving air in and out of the breathing tubes, and connecting that air to blood vessels. The smallest unit of the lung at the end of all the breathing tubes is an alveolus.

  The alveolar wall consists of cells (called pneumocytes) and a very thin membrane which is surrounded by the smallest type of blood vessel, a capillary. The alveolar wall is also sometimes called the interstitium. The close proximity of the alveolus and capillary allow oxygen from air in the alveolus to move into the blood stream, and carbon dioxide from the blood stream to move into the alveolus and be breathed out.

  Pulmonary interstitial glycogenosis (PIG) is described as an expansion of the interstitium because of a gradual gathering of glycogen (a type of sugar) containing cells (mesenchymal cells). Because of the expanded interstitium, transfer of oxygen from the alveolus into the blood stream, as well as the transfer from carbon dioxide from the blood stream into the alveolus, is impaired. In most cases problems with breathing and feeding may either be present at birth or in the first few weeks.

  Breathing often becomes worse fairly rapidly over time, with low oxygen levels and marked increased work of breathing (tugging below and between the ribs).

  In hospital, children may be provided with oxygen, or when the problems get worse may be given support by face mask ventilation or full ventilation by a breathing tube.

  Diagnosis

  Initially doctors may consider that an infection is causing the problem, but as time progresses and there is no improvement (or more typically worsening) the diagnosis of PIG will be considered.

  There is no genetic test for PIG. A lung biopsy is needed to confirm the diagnosis.

  Many children with PIG suffer from congenital heart defects. PIG has also been described in association with several other diseases.
  

  Treatment and outlook

  Most children with PIG will stabilise or improve under treatment with steroids. Of course, treatment of additional conditions such as congenital heart defects will continue.

  Even if most children with PIG are critically ill at the time of diagnosis, most children will improve over time and may show no symptoms by school age.

• Surfactant B deficiency

  Surfactant B deficiency and your lungs

  This is a lung condition caused by Surfactant B deficiency, and may also be referred to as Surfactant B mutations or Surfactant B dysfunction.

  The lungs work by moving air in and out of the breathing tubes and connecting that air to blood vessels. The smallest unit of the lung at the end of all the breathing tubes is an alveolus. The alveolar wall consists of specialized cells (pneumocytes) and a very thin membrane which is surrounded by the smallest type of blood vessel, a capillary.

  The close proximity of the alveolus and capillary allows oxygen from the air in the alveolus to move into the blood stream, and carbon dioxide from the blood stream to move into the alveolus and be breathed out.

  Pneumocytes can be divided into type I and type II pneumocytes. Type II pneumocytes are responsible for the production and excretion of surfactant.

  Surfactant is a complex surface-active mixture consisting of different lipids and proteins which line the alveolar wall. The main function of surfactant is the reduction of surface tension to prevent collapse of the alveoli at the end of expiration. Surfactant has also anti-inflammatory and antimicrobial properties.

  In patients with Surfactant B mutations (changes in DNA) the function of surfactant is impaired. This can lead to a collapse of the alveoli which obstructs the transfer of oxygen into the blood stream and the transfer of carbon dioxide from the blood stream into the alveolus and is often accompanied by inflammation within the alveolar wall.

  The severity of the condition depends on the kind of mutation in the Surfactant B gene but most children develop symptoms during the first days or months of life. Problems with breathing and feeding are often present. Breathing often becomes worse over time, with low oxygen levels and marked increase work of breathing (tugging below and between the ribs).

  In hospital, children may be provided with oxygen, or when the problems get worse may be given support by face mask ventilation or full ventilation by a breathing tube.
  

  Diagnosis
  

  Initially doctors may consider if there is an infection causing the problem, but as time progresses and there is no improvement (or more typically worsening) the diagnosis of Surfactant B mutation will be considered.

  Diagnosis can only be confirmed or excluded by a genetic test. In some cases however a lung biopsy may be considered, where a piece of lung tissue is looked at under a microscope.

  Treatment and outlook

  Very few children with this condition will stabilise or improve under treatment with steroids, hydroxychloroquine and/or azithromycin.

  Lung transplant could be an option for very sick children without improvement under medical treatment but this is technically very difficult especially in young infants.
  

  Most children do not survive their first year.

• Surfactant C deficiency

  Surfactant protein C and your lungs

  The lungs work by moving air in and out of the breathing tubes and connecting that air to blood vessels. The smallest unit of the lung at the end of all the breathing tubes is an alveolus. The alveolar wall consists of specialized cells (pneumocytes) and a very thin membrane which is surrounded by the smallest type of blood vessel, a capillary.

  
  The close proximity of the alveolus and capillary allows oxygen from the air in the alveolus to move into the blood stream, and carbon dioxide from the blood stream to move into the alveolus and be breathed out.
  

  Pneumocytes can be divided into type I and type II pneumocytes. Type II pneumocytes are responsible for the production and excretion of surfactant.

  Surfactant is a complex surface-active mixture consisting of different lipids and proteins which line the alveolar wall. The main function of surfactant is the reduction of surface tension to prevent collapse of the alveoli at the end of expiration. Surfactant has also anti-inflammatory and antimicrobial properties.

  Surfactant protein C is a very important component of surfactant. The main function of surfactant is the reduction of surface tension to prevent collapse of the alveoli at the end of expiration. In patients with Surfactant C mutations the function of surfactant is impaired. This can lead to a collapse of the alveoli which impedes the transfer of oxygen into the blood stream and the transfer of carbon dioxide from the blood stream into the alveolus and is often accompanied by inflammation within the alveolar wall.

  The severity of the condition depends on the kind of mutation in the Surfactant C gene and environmental factors.

  Diagnosis

  Most children develop symptoms during their first two years of life. Problems with breathing and feeding are often present. Breathing often becomes worse over time, with low oxygen levels and marked increase work of breathing (tugging below and between the ribs).

  In hospital, children may be provided with oxygen, or when the problems get worse may be given support by face mask ventilation or full ventilation by a breathing tube.

  Initially doctors may consider that there is an infection causing the problem, but as time progresses and there is no improvement (or more typically worsening) the diagnosis of Surfactant C mutation will be considered. Diagnosis can only be secured or excluded by a genetic test. In some cases however a lung biopsy may be considered, so that a piece of lung tissue can be looked at under a microscope.

  Treatment and outlook

  A significant proportion of children with the condition will stabilise or improve under treatment with hydroxychloroquine, steroids and/or azithromycin.

  Lung transplant could be an option for those whose treatment is unsuccessful and whose condition continues to deteriorate.

• Systemic sclerosis

  Information coming soon.

Follow these steps to help with a diagnosis:

As with all investigations, make sure that you know why the test is needed and any potential complications or risks. The more you understand about what the test involves and why it is required, the easier it will be for you to consent to and support your child in having the test.

• Contact with a specialist centre

  At the point when ChILD is first suspected, your child should ideally be discussed with a specialist centre with expertise in the diagnosis and management of these rare conditions. Speak to your doctor to understand how your child’s diagnosis and management will be guided by interaction with ChILD specialists.

• Prepare for your first appointment

  A diary of the following information (including dates when you can) can help to get a successful diagnosis of your child's condition:

  • Symptoms that you have noticed
  • When the symptoms started
  • What investigations have been performed
  • What treatment has been given so far
  • How many times (if any) has your child been treated in hospital

  If you have an out-patient appointment at a new or different hospital, make sure that the doctors you will meet have access to:

  • Previous medical letters and results of tests, including lung function tests
  • Imaging, including X-rays and CT scans – they can be transferred electronically to the hospital or placed on a CD
  • Short videos of your child (taken on your phone) showing symptoms that might be difficult to describe

• Basic investigations

  These are the most common basic investigations and should be done in all children suspected of having an interstitial lung disease (ILD). They will have little impact on your child and deliver quick results:

  • Taking a detailed medical history
  • Measurement of weight and height
  • Physical examination
  • Measurement of breathing rate
  • Measurement of oxygen saturations
  • Blood gas analysis
  • Chest X-ray
  • Blood tests
  • Lung function tests (usually only in children over 5 years)
  • An exercise test, for example the 6-minute walk test (only in children over 5 years)
  • Sweat test (this is a test for cystic fibrosis)

  
  

• Detailed investigations

  Some more complex and important investigations to help provide a comprehensive diagnosis of ChILD include the following:

  • CT (computer tomography) scan: This is often the most important imaging technique for a child with a suspected chILD as it gives a much more detailed picture than an X-ray. Although it is unusual for a CT scan to give a precise diagnosis, it can confirm the presence of chILD. It can help identify where tissue samples should be taken from for further investigation. A CT scan gives a higher radiation dose than an X-ray so repeated scans should be avoided if possible. Babies and young or sick children often need a general anaesthetic to obtain good quality images for diagnosis as they need to be able to hold their breath and to lie still long enough for the scan to take place. Movement (including breathing) can make the image blurred.
  • Further blood tests: These can offer important information as to which disease it may or may not be.
  • Echocardiogram: This is an ultrasound heart scan.
  • Bronchoscopy: An examination of the breathing passages (airways) of the lungs using a thin tube with a small camera at its tip, called a bronchoscope. Images from the camera show on a screen during the procedure. The procedure is always done under general anaesthetic in children and young people.
  • Lung biopsy: This is usually the final investigation for suspected chILD when other possible conditions have been excluded. This procedure may be done by an open thoracotomy (an incision in the side of the chest) or by VATS (video assisted thoracoscopic surgery). Your doctors, including a surgeon, will discuss with you the best way of obtaining a lung biopsy in your child. The surgeon can look directly at the lung and take small samples of around 0.5-1cm.
    

• Genetic testing

  The following types of ChILD can be diagnosed directly with genetic blood tests:

  • Surfactant Protein B Deficiency
  • Surfactant Protein C Deficiency
  • ABCA3 Deficiency
  • Alveolar Capillary Dysplasia
  • Brain Lung Thyroid Syndrome
  • Congenital Pulmonary Alveolar Proteinosis

  These tests can take from days to weeks to deliver a result after the blood test. The advantage is that they give a clear diagnosis without the need for a lung biopsy (when positive).

After investigation, your child may receive a diagnosis of ChILD

Read our stories from parents who have faced similar situations and see our Treatment page as well as Support. Many parents find this a very difficult time.

• Working towards a diagnosis

  Piecing together bits of information and considering how a condition is evolving over time is often part of how a diagnosis of ChILD is reached.

  This takes time and is naturally frustrating and very difficult for families to reconcile. Often there is ‘working diagnosis’, that needs more information to make a firm diagnosis.
  
  Discuss with your doctors their uncertainties about reaching a diagnosis and what factors and timescales may help them reach a firmer diagnosis.
  

• Dealing with your feelings

  After investigation, your child may receive a diagnosis of ChILD. This can be very difficult news to hear so take your time and ask for a follow-up letter with all the information in it so that you can take the time to understand the diagnosis once the initial shock is over.

  Ask your healthcare professionals for clarification on anything you do not understand and share your concerns as they may be able to alleviate your worst fears.

  You may wonder if you should have noticed symptoms earlier but as the symptoms of ChILD often develop in a gradual way and are incredibly difficult to notice, there is nothing you could have done differently. Often, the symptoms have other common causes for them and as very few doctors will have encountered (or even heard of) these rare ChILD diseases, it is nobody's fault.

• What does the future hold?

  Your healthcare professionals will probably not be able to tell you how things will progress for your child as not enough is known about these rare ChILD conditions yet.

  Parents tell us that this uncertainty, and the anxiety that comes with this, is one of the most difficult things to cope with. It can be helpful to share your anxieties, sorrows and problems. Talk to others (see Support) and let others help you.