Monday, 11 June 2018

Paediatrics is Not a Specialty - top tips for working with young people

Paediatrics is difficult to define as a specialty.  At one point the RCPCH talked about “doctors who look at specific health issues, diseases and disorders related to stages of growth and development.”  Now the RCPCH careers site has a very different note stating, "Whether a paediatrician, GP, children's nurse or pharmacist, our job is to help babies, children and young people thrive." I'm guessing that the RCPCH realised that it wasn't just doctors and it certainly wasn't just paediatricians who fitted the original description.

In fact paediatrics may not be a specialty at all.  It could be defined as the art of treating children differently from adults by knowing what diseases affect them, how they respond to illness and how to use that knowledge to help them during their illness or prevent them from becoming ill.

Anyone who works with children in a healthcare setting should study of the art of paediatrics.  We all need to develop our skills in assessing and treating ill children as well as becoming experts in all the other aspects of child health including safeguarding, growth and development.  Children and young people are different in so many ways and it takes a bit of effort to get good at working with them but it is completely worth it.

What is different about children and young people that requires a different approach and different skills?

Children respond differently to illness - Physiological changes can be dramatic in uncomplicated viral illness making the recognition of complicated infection difficult
Children may not localise, report or recognise symptoms - This is why constipation and UTI are often only diagnosed when they have been prolonged.
Children often present with something normal - This often happens because an adult is concerned and doesn't know that the symptom is normal.  One example is knock knees in children.
The overall likelihood of significant pathology is low - Much of paediatrics is about diagnosing normality or at least that the illness is uncomplicated and does not require medical intervention.  The other side of this coin is that the routine nature of a good outcome can lead to complacency and impairs our awareness of complications and significant pathology.
Children are vulnerable - As well as the safeguarding element of caring for children and young people, we have to consider how difficult it is for them to feel safe in a healthcare setting.  It is confusing and intimidating and it is too easy to forget to keep the child at the centre of the process.
There is a lot of uncertainty that goes with the assessment of children - paediatrics is often compared to veterinary medicine because we end up relying more on what we see.  It is fairly usual to find that we can't get specific symptoms and that our ability to examine is limited by the child's interaction.

Last week, I went onto TwitFace and asked the people who were online what their top tips are for working with children an young people.  What follows is based on some of the great responses I recieved.

Starting with the general advice:

There were also loads of tips for examining children:
I haven't been able to include everything and in some cases there were recurring themes which I have categorised together.  There were quite a few specific things that people have found to be useful in paediatric examination, some of which are listed here:
  • The guess what's in the tummy game.  I have a high success rate with guessing sausages.  However you go about it I would highly recommend this approach to abdominal examination.  It's probably quite scary for a child to have a stranger press their tummy, but if it's a game that seems to be a different matter.
  • For assessing gait, get the child to walk towards their parent rather than away from them.
  • For ENT examination:  Tell the child: "I have a magic fairy/dragon detector (ear thermometer) that goes beep when a fairy is in the room. If it beeps I have to check their ears and throat with my magic torch to make sure it isn’t hiding in there."  I have to try that one.
  • For respiratory exam, ask them to blow out the candles on an imaginary birthday cake.
One place even had a departmental rabbit.  I can imagine that would work to settle many an otherwise inconsolable child!

Paediatrics may not be a specialty but it is an art.  How you approach that art is up to you but whichever you go about it the end result should be the same:  The child will get the best care possible and you might be having some fun at the same time.

Edward Snelson
Possibly not a Paediatrician

Disclaimer - All the views expressed here are solely those of the author.  Any references to Royal Colleges are entirely fictional and should not be used as a reason to revoke the author's invitation to the annual RCPCH cheese night.

Acknowledgements: Thank you to all the people who shared their tips and tricks via social media or face to face.  More importantly, thank you to all the children who put up with us while we figure out how to do the whole paediatric examination thing.  Your patience and tolerance is appreciated.

Thursday, 7 June 2018

The Right Sort of Confidence - (Easter Egg: Acute abdominal pain in children)

I feel pretty confident that my car has the right amount of oil in the engine and air in the tires.  Why?  because that has been the case every time I check these things.  So why bother checking?

Paediatrics is a dangerous speciality because the usual outcome of any child presenting for assessment is that everything is fine.  Fever?  It's probably an uncomplicated viral infection.  Rash?  Virus.  Lump in the neck?  Virus.  You get the idea.

As a result, any one of us can become so used to the benign outcome that we don't expect the dangerous problems or the unusual causes of childhood symptoms.  This is called availability bias.  The last 50 children with this presenting complaint had a virus and got better, so this patient is likely to be the same.

Of course the statement about the likelihood is true, however people don't bring their children to us just for a probability estimate.  We are there to assess whether there is a significant problem that requires intervention.  To get there, we need to know what to look for.

Abdominal pain in children is a good example.  Children often get abdominal pains.  One of the most common presentations is abdominal pain during a febrile illness.  Most likely cause?  Virus.  I suspect that the significant pathology that is most often considered in this situation is appendicitis.  Appendicitis is relatively rare in younger children but paradoxically more difficult to diagnose, so while the chances of a 3 year old having appendicitis is very low, so are the chances that a 3 year old with appendicitis will get this diagnosed easily.

Appendicitis is at least on our minds and so we're probably not going to miss it through failure to look.  There are plenty of causes of abdominal pain that are easily missed for various reasons.  Lower lobe pneumonia, for example, is easily missed because it isn't in the abdomen.  Testicular torsion is easily missed if it isn't looked for.  You'd think that if a child or young person had a problem with their genitalia they might mention that.  They often don't.  If you don't look for torsion, you won't find it.

Here's a brief overview of some of the easily missed causes of abdominal pain in children:
Here is a more extensive list of possible causes of abdominal pain in children.

Going through these, starting at one o'clock:

Mesenteric Adenitis - Yes, children with viral upper respiratory tract infection can get acute abdominal pains and can even have localised abdominal tenderness.  Children with more significant causes of pain can also have URTI, so if there are red flag signs or symptoms you should still take these seriously.
Non-IgE food allergy - This can cause acute abdominal pain but paradoxically is a diagnosis best not made acutely.  History, a food diary and follow-up are the way forward when food allergy becomes a possibility.
Gastroenteritis - When vomiting precedes abdominal pain then this makes gastroenteritis more likely.  Similarly, diarrhoea is a strong indicator of viral enteritis.  However, there is no such thing as always, so careful abdominal examination is key and signs that suggest a surgical cause should still lead to referral.
Gynaecological - The main thing to say about this is that it is a common pitfall to forget to even consider this possibility in children.  How often do you think ectopic pregnancy is considered in the differential of a 13 year old with acute abdominal pain?  It should always be remembered as a possiblity.  Do a pregnancy test.
Constipation - This is possibly the most common cause of afebrile acute abdominal pain in children.  There are two main pitfalls.  The first is to miss the diagnosis because the child or parent doesn't think the child is constipated.  The second is to think that because the presentation is acute, the problem just needs a brief period of treatment.  If they are constipated enough to present with acute pain, the problem is chronic and should be treated as such as per NICE guidelines.
Urinary Tract Infection - Abdominal pain +/- vomiting without diarrhoea is a common way for children to present with UTI.  There is no absolute rule on when and when not to test a urine but it is fair to say that significant diarrhoea usually precludes it for a couple of reasons.  In all other cases of acute abdominal pain, it is usually a good idea even if interpreting the result is not completely straightforward.
Colic - Truly a diagnosis of exclusion, but this can be a good history and examination. What to do with colic is covered here.
Appendicitis - Uncommon but not so rare that you won't see a case every now and then. Picking them out from the crowd can be difficult.  Good simple analgesia and reassessment after an hour is often a helpful discriminator for the grey cases if you can do that.
Testicular torsion - Inguinal and genital examination is part of the examination of a male presenting with abdominal pain.  Do it, even if the last 100 times were normal.
Intussusception - Rare but deadly.  Episodes of pallor and signs of being significantly unwell are reasons to suspect intussusception.  Bloody and mucousy (recurrent jelly-like) stools make it easier to diagnose but may be a late sign.
Diabetic Ketoacidosis - It is very easy to see how first presentations are initially diagnosed as viral illnesses.  If you've got a child who's a bit more lethargic or subdued than your typical gastroenteritis case, or if there is a report of polyuria, test a glucose.

In most cases, significant causes will be excluded by a thorough history and examination.  Often a urine test is a good idea and sometimes a second opinion will be necessary.  Abdominal X-ray is almost never useful in making a decision about referral.

Paradoxically,  the wrong sort of confidence comes from repeated experience of nothing bad happening.  The right sort of confidence comes from knowing that bad things will happen and knowing that we're ready for that eventuality.  This often happens once you've experienced the sharp end of an unexpected diagnosis.  If that has happened, congratulations!  You're now an expert.

Edward Snelson
Experienced if not Expert

Disclaimer - Experience doesn't always lead to expertise but it's a fairly important element. Bad experience is a good wad to develop great expertise but only if you have all the right elements in place to ensure that you learn without becoming a second victim.  I would like to see more work in that area, especially at the Primary/ Secondary Care interface.

Wednesday, 23 May 2018

Quick and Easy FOAMed - Fallacies and Facts About Foreskin Problems in Children

In case you hadn't noticed, there is now a guideline for everything.  It is impossible to keep up. FOAMed can be really useful in that respect because it should keep a finger on the pulse for you and give you a condensed version of the important things, allowing you to be selective about when you go into something in more detail.  The way it works is that I read the guideline, just in case you don't get the chance.  (insert cheeky winking emoji here)

Nor can you rely on guidelines, alerts and journals to cover everything, despite the sheer quantity of them.  The nature of FOAMed is that it often covers the things that haven't earned a guideline, are not deemed worthy of an alert and have too little academic value to have a published article.  Some things that are over-represented in practice are under-represented in paper.  By way of example, I give you foreskins in children.  I think that the lack of publications on the subject is surprising considering the number of children attending primary and secondary care with this problem, and considering how much is often misunderstood about foreskins in pre-pubertal children.

At some point in my medical training I remember being taught that uncircumcised penises should easily retract by about 3-4 years old and that they should be kept clean.  Balanitis was seen as evidence of poor hygiene and so we were told that more cleaning was the solution.  Foreskins that were ‘non-retractile’ were considered abnormal and if there was recurrent balanitis or ballooning, the child should be considered for circumcision.  We now believe that all of this is untrue.  It is quite normal for the foreskin to remain adhered to the glans until they hit puberty, whenever that may be.  Ballooning is within normal limits and balanitis is often due to unnecessary attempts to retract or clean under a foreskin.  Recurrent balanitis is usually an indication to leave the foreskin alone, rather than to cut it off.

So I know that I was taught something that later turned out to be untrue and I know that many clinicians in both primary and secondary care haven’t heard the good news.  Why?  Presumably because it isn't seen to be worth a guideline, alert or journal article.  There is stuff out there, but not a lot.  This was the best article that I found. (1)

But the lack of literature is not a problem in the brave new world of FOAMed.  FOAMed comes in many different shapes and sizes.  Often it takes the form of a written piece, but some have embraced the infographics approach.  Most notably there is the excellent library of infographics that has come out of the Derby Emergency Department. (2)  I was inspired by Ian Lewins making infographics sound like a good thing so I'm having a go with it.  Here's the result:

An infographic is, by nature, pithy and lacks detail but hopefully it gets the job done.  I've gone for substance over style. I know that if I had given the job to a medical student, they probably would have been much better with the visual effects.  They would also have made sure there were more pictures.  Somehow, this didn't seem like the best subject with which to take that step.

Edward Snelson
President of the Sir Lancelot Spratt Association
Disclaimer:  Anyone can do this stuff.  If you want to have a go at making infographics and want to find out more about rickrolling, click this link.

  1. Drake T, Foreskin problems in boys, Trends in Urology and Men's Health, March/April 2014

Wednesday, 16 May 2018

Time for Child Advocacy - 10 things to keep kids safe

Don't you love it when someone brands something that you've always been doing?  Advocacy is nothing new, but by making a big deal of it, we are all prompted to think about how we can do more of it and do it better.  Every consultation involving a child or young person will tend to include a bit of advocacy.  I am doing it every time I tell a parent that when their febrile child is refusing to drink, that usually means that they are in pain.  Parents sometimes think that paracetamol and Ibuprofen are just for reducing fever.  Part of my job is to put analgesia on the agenda.  It is the perfect time to do it because this is when the parents want their child to feel as well as possible.

Similarly, the impact of safety advice is greatest following an injury.  So when a child or young person comes to me with a mishap, I try to work a bit of prevention in alongside the cure.

Injury is the leading cause of death in children over the age of one in the UK. (1)  So, while we worry about sepsis and meningitis, preventing injury may be the real battleground.  Injury is inherently preventable, as demonstrated by the massive difference between rates in different countries.  It is not just lethal injury that is important.  In fact, to the children themselves it is the debilitating injuries that really matter.  Missing a sporting event or the ability to swim just before a holiday is the end of the world.  Or at least it is when 'the future' is essentially the next month or so.

What I do is to try to throw in something relevant to the presentation.  Whether injury or ingestion, there are lots of ways that we can make the environments of children and young people safer.  Here are a few that are worth spreading the word about to parents and colleagues:

1. Warn parents of babies and toddlers about common choking hazards

Have you ever wondered why pen lids have a hole in the top?  Before that little innovation, these were common choking hazards.  Anything that fits neatly into the windpipe runs the risk of a fatal choking episode.  The list of dangerous things includes many food and playthings that parents readily give to their children.

I think that any household mishap is a good opportunity to warn parents about choking hazards.  Prevention can include avoidance.  Supervision is also great but only if you know what to do, and with choking, prevention really is better than cure.

2. Make sure that children can't get hold of button batteries

If you were not aware of this, button batteries are incredibly dangerous to children.  There is a misunderstanding about these miniature killers.  It is not the contents leaking that are dangerous, it is the electrical current which forms corrosive chemicals outside of the battery.  Button batteries have become more powerful, in order to meet the demands of today's toys and gadgets.  When swallowed, the current may burn a hole in the gut (usually the oesophagus) and bleeding can be fatal.  A swallowed button battery needs to be located as an emergency in case it is stuck, as these carry the highest risk.

I find that many parents don't know about this, so I often mention it when a child has swallowed something concerning but less harmful, like a diamond ring.

3. Make sure that liquid gel detergent capsules are kept away from children

Ask any ophthalmologist what common household item is most dangerous to children's eyes and I am willing to bet that they say liquid gel detergent capsules.  Why?  They are the perfect thing to cause massive damage.  Firstly, they look very appealing to a child.  They are brightly coloured and a bit like something that might be good to eat.  If bitten into, the contents come out under pressure, so the eye has no time to protect itself from the contents.  The contents themselves are a highly concentrated alkali which will burn and dissolve the thin layers of the eyeball.  While the industry has made some moves to warn people to keep these away from children, such messages can be interpreted as a standard bit of advice, which does no justice to the fact that these capsules are far more dangerous than the standard bottles or boxes of detergents.

So when a child has had a mishap with another item, I like to warn parents about other things that they may not have thought about.

4. Recommend that all children with a bike wear a bike helmet.

Heads injuries are the most common cause of fatal injury in children.  Bikes are great fun and a good way for children to keep fit.  Unfortunately, injury is all about physics.  I have yet to see a child run into something and have a significant head injury.  Bicycles however, allow a young person to gain enough momentum to do real damage even if another vehicle is not involved.  While it can be difficult to persuade young people to wear helmets, they are the must have accessory for anyone who likes their brain or their face.  Road rash on the face is not a good look and helmets do a decent job of protecting the face from being badly grazed in a fall from a bike.

I emphasise the facial injury as much as the head injury prevention as it often means more to the young person involved.

5. Advise a bit of trampoline safety

Trampolines are a favourite for all ages.  They are also one of the biggest sources of injuries that come into children's emergency departments.  While I am not suggesting that trampolines should be avoided, the risk of broken bones can be minimised.  One of the common factors in many of the worst trampolining injuries that I have seen is that there has been another person involved.  The worst injuries tend to occur when a small child is on the trampoline with an older child.  I would recommend that younger children in particular should never have someone larger than them on the trampoline.  Ideally, they should be on the trampoline alone, with onlookers cheering them on.

6. Make sure that parents lock up medicines

Medication packaging always has on it 'keep out of reach of children.'  What this fails to take into account is the incredible resourcefulness of children who may seem to small to get up to cupboards or high shelves.  I can tell you from experience that nowhere is safe.  The only completely safe place for a medicine is in a locked cupboard or box.  Nor can you rely on 'child proof' containers to prevent accidental poisoning.  Child proof containers seem to be adult proof (It can't be just me that struggles with the tops) while children who have time on their hands always seem to get them open in the end.

7. Know about the surprise household poison - plug in air fresheners

Many plug in air fresheners contain essential oils.  These chemicals are potentially incredibly poisonous due to their ability to dissolve into brain tissue.  Parents are frequently surprised by this fact so it is well worth letting people know about this dangerous household item.  People are also surprised by the ability of toddlers to drink the contents of these plug ins if they get hold of them.  I don't know how they do it.  And why won't they eat their vegetables???

8. Warn parents to beware of the sun

When the sun comes out and children quite rightly make the most of it, we often end up seeing children with quite severe sunburn.  Babies are especially at risk due to their thin skin and lack of protection from the sun.  Make sure that people know that children can get deep burns from the sun and that prevention is key.  Children are also vulnerable to the dangers of overheating so hydration and sun avoidance are important when the sun is out.

9.  Remind adolescents to respect water

It is great that young people use the opportunity of time off school to go and have a bit of an adventure.  One way that this sometimes goes very wrong is when water is involved.  Getting into trouble in water is all too easy.  The simplest way to avoid the danger is to make sure that all swimming is done in appropriate areas.  Tempting though it is to jump into a reservoir or an abandoned quarry full of water, this is very high risk.

10.  A surprise danger – twilight

Now for the sciency bit…  Twilight is a very dangerous time for pedestrians and young people are already very much at risk due to their lack of perceived mortality.  Why is it dangerous when the sun rises and sets?  The answer is probably due to a little known chemical (found in the eye) called rhodopsin.  This is the chemical that enables the eye to adjust to lower levels of light.  The trouble is that it takes many minutes to produce the chemical and only seconds for a flash of light to get rid of it completely.  As a result, drivers can have their ability to see reduced very suddenly by a moment of setting or rising sun, allowing a person in the shadows to become almost invisible. (3)

It is important to teach young people road safety, but also to let them know that at certain times of day, drivers may not see them at all.
We're already making every consultation matter.  Giving parents a little suggestion every now and then about how to make their child's environment a bit safer is just another way of adding to the difference we already make.  Paediatrics is so rarely about preventative medicine but when a child has a mishap, we have a golden opportunity to discuss ways to avoid the next accident.

Edward Snelson
Chronic Avoider

FOAMed is free.  The clue is in the name.  That said, if anyone would like to celebrate their enjoyment of the free open access education provided by GPpaedsTips by helping children to receive the best possible care, I have set up a donation page where I am raising money for a new Sheffield Children's Hospital Emergency Department.  For more information about this or to donate, click on the link in the Just Giving logo:
Image result for just giving logo
  1. RCPCH, "Why children die: death in infants, children and young people in the UK"
  2. AAP, "Prevention of Choking Among Children", February 2010

Tuesday, 8 May 2018

ECG in children - an amuse bouche (and what to do with one)

Food etiquette is a minefield.  I remember the first time I was presented with an amuse bouche.  I had no idea why it was, let alone what I was supposed to do with it.  One minute later, with the tasty morsel in my belly, I realised I had really over-thought the whole thing.  Also, I was still hungry.  Non-acute paediatric ECG is a lot like that.

Some tests are so simple, usually because they are quantitative.  You do a blood sugar and you get... a blood sugar.  Some tests are much more qualitative, such as Chest X-ray.  Show a chest X-ray to half a dozen radiologists and you may be surprised by the range of interpretations.  ECG in children definitely falls into the second category in that it is a test which requires interpretation.  The interpretation of an ECG is fairly standard, but I've never yet met a standard child or a standard clinician.

There are many reasons why an ECG might be done for a child.  I am not talking about during an acute presentation such as a severe tachycardia or other signs suspicious of a cardiac cause for a child to be unwell.  I am talking about ECG in a child who is well, but had a symptom that warranted an ECG.  If you want to know about the kind of critical care ECG interpretation best done wearing a cape and with underpants on the outside of your trousers, you might like to listen to the PEMplaybook.
If your cape is in the cupboard and underwear is wherever you normally keep it, then ECG is a more fickle friend.  When an ECG is normal normal then that's great but it's not the end of the story.  Often it appears abnormal, because paediatric ECGs look different much of the time.  In a BMJ article about ECGs, the authors write, "Chest pain in children is rarely cardiac in origin and is often associated with tenderness in the chest wall. Electrocardiography is not usually helpful in making a diagnosis, although a normal trace can be very reassuring to the family." (1) That is all very well if with a 12 lead ECG you can tell them that all is normal.

So what is the problem with paediatric ECG?  Well actually there are two problems.  The first is the issue of things that look abnormal and are not.
Much of the differences in paediatric ECG are to do with the initial right sided dominance.  The other thing that can be a factor is physics.  The ECG may show up as LVH, RVH, atrial enlargement etc, but this is often because there is just very little in the way of chest wall between the sticker and the myocardium.  You don't get this problem in children with a more substantial chest wall.  Simply put, in a small or skinny child, large waves are usually normal. If something appears big, look at the child and check the axis.  A skinny child and a normal axis means that the "LVH by voltage criteria" is probably a lie.

Knowing these things helps us to be able to say more often, "This is a normal ECG."

Then there is the opposite problem: a 12 lead ECG done when asymptomatic does not rule out significant pathology.  Take this case study as an example:

A 12 year old girl presents having had a collapse while playing tennis.  She had no palpitations or chest pain and simply recalls feeling faint just before she collapsed.  The adult playing tennis with her describes a sudden collapse, while she was walking t pick up a ball.  When they ran over, the young person was unresponsive for only a few seconds before slowly coming around.

Clinical examination is normal.  The only other history of note is in the family history - a sudden unexpected death in infancy of a 9 month old sibling.  

Would you be happy to rule out a cardiac arrhythmia based on a resting, asymptomatic 12 lead ECG?  With that history, I wouldn't recommend it.

So, if an ECG in a child who is currently asymptomatic has a lot of false positives and false negatives, what is it useful for?  The answer to that is that it should mainly be used to answer specific questions.  For example, in the case above, I want to know the corrected QT interval.  A 12 lead ECG will tell me that.  In fact, resting asymptomatic ECGs are mostly useful for checking rhythm and intervals.

Morphology and high voltage account for most of the false positives and normal rhythm can be a false negative.  Both these things are fine, because a 12 lead ECG is simply an amuse bouche.  If you aren't hungry (no red flags), an amuse bouche is simply a tasty mouthful which won't fill you up.  It is debatable whether it is even needed in a child who has had a typical faint with no red flags.

If you are hungry (red flags in the history or examination), don't rely on an amuse bouche, which should just be there to keep you happy until the real food arrives.  What you have for your main course depends on where you work.  Perhaps you have direct access to 24 hr ECG and cardiac echo. Me? I phone a friend to do these things for me.

Edward Snelson
The Gourmand of Child Health

Disclaimer - I may not have had all of the ECGs the right way up.  That could explain some of the abnormal morphology.

  1. Steve Goodacre, Karen McLeod, Paediatric electrocardiography, BMJ 2002;324:1382
  2. PEM playbook EKG killers

Tuesday, 24 April 2018

The Evil Twin - Orthopaedic Problems in Children Pt 2: Painful Presentations

Pretty much every individual symptom in children is likely to be something which is either normal or at very least will follow a benign course. Orthopaedic presentations are no exception.  If you've already read part 1 (orthopaedic problems in children) and came away with the impression that almost all children with bow legs, knock knees, in-toeing etc are essentially normal and that the problem is likely to self-resolve, you're not wrong.

This is one of the wonderful things about paediatrics.  Many concerning presentations are actually normal, allowing us to feel like we've done something great just by reassuring a parent that their child doesn't have anything wrong with them.  Also, many problems self resolve allowing us to take a light touch approach, avoiding unnecessary tests or treatment, always remembering to act in the best interests of the child.

These factors are also one of paediatrics greatest difficulties.  Everything is normal, except when it isn't and everything in children's health has an evil twin.

Let me give you some non-orthopaedic presentations as examples.
Paediatric orthopaedics is similarly riddled with presentations where the likelihood is that it is something that needs no intervention, while there always exists the possibility of a much more problematic pathology.  Like the evil twin (often used as a complicated anti-hero in literature and film) concept, the pathology that we have to be wary of usually shares many characteristics with the more benign explanation for the symptoms.  Since common things are common, the temptation is always to presume the more likely option. So how do we recognise the more dangerous orthopaedic problems, while avoiding over-investigation and over-referral?

First, it is important to know what is typical so that we can know what is atypical.  For example, irritable hip is usually seen from the age of one to six years old.  It can occur outside of that age range but is uncommon and so is diagnosed with an appropriate caution.

If a preschool child has a fall, the outcome is usually no injury or a fracture.  Sprains are uncommon in this age group because they are too flexible to easily strain a ligament to the point of injury.

Once we are familiar with what is both normal and common, it is important to know what the signs are of the common and expected, we need to know what should alert us to the more significant yet less common pathologies.  In other words, what are the red flags?

There are some red flags that are fairly reliable and these are listed here.
However some of the red flags that are listed elsewhere are rather contextual, proving the evil twin problem.  For example, Arthritis Research UK lists nocturnal pains as a red flag symptom (1) while NHS choices lists nocturnal symptoms as a typical feature of growing pains (2).  That is  why red flags will only get you so far.  Sometimes certain presentations are a set piece.  Here are a few examples:

A 12 year old presents with bilateral knee pain, worse on the right.  The pain is worse after sports and is particularly bad on stairs.  He is limping.  Both knees have full range of movement and no effusion.  The tibial tuberosity is swollen and tender in both knees.

This is Osgood-Schlatters disease.  Simple.  This problem of adolescence is more a biomechanical problem than a true disease process.  There is little that can be done for this problem apart from symptomatic treatment and a careful management of the balance between being active and being in pain.  An orthopaedic surgeon can't fix this problem unfortunately.

A 7 year old presents with a limp and pain in the hip.  There is no history of injury.  They are not unwell or febrile.  Simple analgesia has helped but the limp is still obvious.  Examination is normal apart from a reduced internal and external rotation of one hip.

There are various possible explanations for this presentation, however index of suspicion for Perthe's disease has to be very high.  The mysterious onset of symptoms that is typical of Perthe's diease makes it a difficult diagnosis.  The early recognition of the disease is further hampered by the tendency that children have to reduce activity instead of increasing their complaining.  Orthopaedic surgeons don't have a magic treatment for Perthe's but will do everything they can to reduce the progression of this difficult disease.  X-ray or referral at presentation is recommended for a patient like this.

A 13 year old presents with what they think is a knee injury.  They have had some left knee discomfort which was made much worse by running yesterday.  Today, the pain is significant despite analgesia and they have a marked limp.  The most notable clinical finding is that movements of the left hip are restricted by pain.

This could be a muscular or ligamentous injury.  However it is also possible that this young person has a slipped upper femoral epiphysis.  The growth plate in adolescents is at risk of fracture and the subsequent movement can cause permanent damage if not treated as soon as possible.  These presentations are tricky as they come with a story that sounds more like a straightforward soft tissue injury.  The important thing is to have a high index of suspicion and a low threshold for X-ray or same day referral.

Edward Snelson
Specialising in conjoined Meducaction

Disclaimer: Once again, many thanks to the team of orthopaedic surgeons at the Sheffield Children's Hospital. This concludes the planned mini series of paediatric orthopaedic posts but if you have further questions or simply wish to tell us your favourite orthopaedic surgeon joke, please post in the comments box below.

  1. Foster E et al, Growing pains: a practical guide for primary care,
  2. Growing pains (recurrent limb pain in children), NHS choices website

Wednesday, 18 April 2018

Why Do Different Children Wheeze Differently? - Simple, but first you have to understand all of paediatrics (also simple)

When a child or young person has one or more wheezy episode, there are various possible causes.  The vast majority of paediatric wheeze is caused by bronchiolitis, viral wheeze and asthma.  It is easy to confuse these conditions, but clarity of diagnosis has real benefits when it comes to providing evidence based treatment.

We know that getting the diagnosis right isn't straightforward, possibly because there are no tests which reliably distinguish these entities from each other in children.  For example, evidence suggests that 50% of children diagnosed as asthmatic do not have asthma (1).  One knock-on effect of any diagnostic difficulties is that people make up rules for us.  "Asthma should not be diagnosed under the age of 5 years."   "Inhalers don't work under the age of 12 months."   These rules are meant to be helpful, but they are both wrong.  If you were only playing the odds, living by these rules would be the way to go, but clinical medicine is also about pattern recognition.  If it looks like a duck etc.
I think that it is possible to embrace the rules, while also knowing when to break them.  I believe that there is a simple model for understanding paediatric wheeze which fits into the probability model and the pattern recognition model.  It's fairly simple and all it requires is a good understanding of all of paediatrics.
Paediatrics isn't the art of learning 30,000 rare conditions.  Paediatrics is mostly about understanding what conditions affect children at different ages and how children respond to those illnesses.  That in turn allows us to recognise and treat appropriately wherever possible.  When it comes to infections and immune responses, unsurprisingly the immune system plays a big role.  Of course a child's immune system goes through several stages and each one dictates a different response to infection and allergens.

How does a baby fight infection?  In simple terms, they don't.  Inherited antibodies do most of the work for the first few months.  Few pathogens get past these antibodies and so the baby's own immune system does very little.  This has lots of implications.  Infections that do occur are unlikely to be common viral illnesses and whatever the pathogen, the baby will be at greater risk from that infection.  Even the recognition of an unwell baby is affected by their lazy immune response.  Temperature of 40C in a 7 day old?  Pull the other leg.
These maternal antibodies eventually run out.  The immune system has to learn and develop.  Older children, like adults have a complex and clever immune system which has stored a wealth of information about the pathogens in their environment.  This allows the older child to produce a response to infection that is not just complicated but sometimes over-complicated.
So how does a human survive in-between losing maternal antibodies and learning a more complex immune response?  In scientific terms, their immune system goes nuts.  You have seen it yourself: even with a relatively simple and uncomplicated viral infection, the younger child can have very high temperatures, various rashes and of course viral wheeze.  Other things that are common in this age group are quite possibly in part due to this exaggerated immune response - irritable hips and febrile convulsions.
These three ways of responding to infection align very nicely with the three entities that commonly cause wheeze at different ages in children.

So, the rules about age do have a solid basis.  Would you diagnose asthma when a six week old becomes wheezy?  Please don't.  Would you diagnose bronchiolitis in a 12 year old?  No.

Age alone does not give you the diagnosis since there is some overlap.  Thankfully, because each condition represents a different immune response, they each present with slightly different clinical features. As a result we can combine probability with pattern recognition.  The best bit is that the pattern recognition fits well with these three immunological stages of childhood.

What happens when you are a baby and a virus causes a respiratory tract infection?  In most cases, the answer is simply wetness.  Bronchiolitis is what you might expect from an immune system that has not yet fully woken up from its cocoon of maternal antibodies.  Bronchiolitis tends to slowly progress over days from cough and coryza to wheeze and suboptimal feeding, finally ending up with a variable degree of respiratory distress.  It progresses over days.  The severity and progression of these symptoms will vary from child to child, however the gradual onset is characteristic.  This is not to be confused with deterioration, which can be sudden, especially in high risk babies.

Viral wheeze by contrast tends to come on quickly, over hours rather than days.  This is because in viral wheeze is a different response to the same viral trigger.  In children between the ages of about 1 and 6, when the immune system sees a new virus, it tends to go a bit crazy.  One of the effects of this immuno-enthusiasm seems to be that that many children experience bronchospasm as part of that immune response.  So in addition to being able to tell which is more likely (bronchiolitis or viral wheeze) by the age of the child, the rapidity of the onset of the wheeze is a clue.
Why does it matter that we tell the difference?  These two different entities respond differently to treatment.  The slow development of inflammation and wetness in the airways that is bronchiolitis does not respond to bronchodilators while the bronchospasm of viral wheeze does.  This is probably the reason for the perpetuated myth that children under the age of one don't respond to beta-agonists.  They do, but only if they have bronchospasm (viral wheeze) as opposed to mostly wetness (bronchiolitis).

Finally, when your immune system moves from the "shoot first, ask questions later" mode into adult mode, asthma becomes the most common cause of wheezing in children and young people.  The trouble is that this isn't something that happens suddenly and it certainly isn't the case that there is a consistent age for this to happen.  Once again though, odds are very much affected by the age of the child.  Does the 8 month old have asthma?  No.  Does the 15 year old have episodic viral wheeze.  Almost certainly not.  Once again, the fact that the different entities represent different stages of immune system maturity translates into both probability and pattern recognition.  The 3 year old is probably having episodes of viral wheeze, but this will be confirmed by the fact that all episodes are precipitated by viral illnesses and the lack of interval symptoms.  The 10 year old probably has asthma and if this is the case they will be having episodes of wheeze not just when they get viral illnesses.

This explains the contradictions between all of the things that we know about asthma in children.  We are told that we shouldn't diagnose asthma under the age of five.  That rule works well from a probability point of view but not from a pattern recognition point of view.  What would you do if a 3 year old has a chronic cough and multiple episodes of wheeze that are not all provoked by viral illnesses?  I think that this child might be the exception to the probability rule.  Equally, in a 2 year old with chronic cough and no history of wheeze the temptation to diagnose asthma is a dangerous one given both the lack of  probability and the absence of a classic history.
Understanding the way that children respond to infection at different ages tells us a lot about where (what age) to look for each diagnosis and what to expect (the classic history) to find in order to confirm that diagnosis.  This allows us to maximise the chances of giving the most appropriate treatment, most of the time.

When there is a discrepancy, we need to be aware that probability and pattern have not agreed, and have a low threshold for rethinking.

Edward Snelson
Occasional rule analyst

Disclaimer: No-one understands all of paediatrics.  I mean really, who can explain why children will eat glue and drink air freshener but refuse to eat the food that you want them to eat?  That's why it's best to stick to the basics (like immunology) and leave the complicated stuff to the parents.

  1. Ingrid Looijmans-van den Akker, Karen van Luijn and Theo Verheij, Overdiagnosis of asthma in children in primary care: a retrospective analysis, Br J Gen Pract 2016; 66 (644): e152-e157