Wednesday, 25 January 2017

The Well Covered Wheezer

Guidelines almost always dedicate themselves to 'what to look out for'- the red fags and risk factors.  Often, we go to a guideline in order to learn about a condition, only to find that we should be afraid, very afraid.  I think that the tendency for the glass-half-empty factor in guidelines is almost certainly due to the understandable desire to err on the side of caution.  When you are writing a guideline, you are very aware that if (when) a patient has a bad outcome, the guideline's recommendations will be critiqued.

However, I don't want my doctor to intentionally err at all. To be honest, the error being on the side of caution is very little consolation.  Unnecessary tests, treatments, referrals and admissions are not what I want.  I want my clinician to be thoughtful and careful, but courageous, not risk averse.   I believe  that calculated risk is a necessary part of practicing medicine well, and so struggle with guidelines that give us the impression that we have to follow a certain pathway even when our instinct tells us that this is not needed.

Of course, I know that many of you will now be thinking, “Guidelines are just guidelines.  You don’t have to follow them.”  While this is of course a true statement, try telling this to a clinician who has been to court regarding an adverse outcome.

I don't want to return to an era bereft of guidelines.  That was no fun at all.  Someone else knew what you were supposed to do, most of the time.  It was your job to guess what was expected of you and then find out afterwards if you were right, rather that to be told beforehand.  However, we need to be aware of the negative effects of guidelines, so that we can protect against these.  (1,2)

I do feel that the guideline era has taken some of what used to be taught and allowed this to drift into mythology.  So, in the interest of history, I thought that I would explore what the guidelines often miss out – the signs that are reassuring.  When marking some assignments for the Primary Care Paediatrics course at Sheffield Hallam University, I was delighted to find the oldest reference that I have ever seen in one of these submissions.

Cassell’s Household Guide to Domestic Medicine (1886) - “…on the minutest air-tubes the cells of the lungs are placed… inflammation of these tubes is one of the most fatal diseases in our climate…The child is quickly bereft of its usual liveliness… the breathing is quick and the nostrils expand more or less… All these symptoms are worse if they occur in delicate children…”(3)

The first thing that struck me about this was that in Victorian Britain, the pathophysiology of bronchiolitis was already known.  The second was that they recognised that scrawny babies with bronchiolitis were the ones to worry about.  This brings me onto the well covered wheezer.
In the days before guidelines, I learned paediatrics by trial and error with a degree of question and answer.

Me: “This child is very wheezy.”
Consultant:  “They’ll be fine.  They’re a fat, happy wheezer.”
Me: “So because they’re a bonnie baby and smiling, they’ll be fine?”
Consultant: “Pretty much.”

I don’t know of any research demonstrating the protective benefits of an extra pound of subcutaneous fat when suffering with bronchiolitis.  What I can tell you is that 20 years on, I’ve never had cause to feel misled by this conversation.  That is partly because I leaned the difference between red flags and those that were more of a blood orange colour.

I would say that it is only the 'significant tachypnoea or recession' which could be negated by other reassuring factors such as being well covered and cheerful.  I also think that this is probably self fulfilling: children with the other red flags are too significantly affected to actually have any reassuring features.

What is also interesting is that, in a straw poll of ten junior doctors, none had heard the term ‘fat happy wheezer.’  This is not down to modernity either.  None of the doctors in question had heard it said that habitus was worth considering when assessing a child with bronchiolitis.  I put this down to an overemphasis on red flags and risk factors, without justice being given to reassuring signs.

So, I am going to appeal to two groups of clinicians to help restore balance to The Force:

Firstly – all you experienced, common sense clinicians, please comment below and let me know what other things are reassuring signs which might be unproven but tell you not to be so worried.

Secondly – all you academics, please research these things and get us the evidence to back up what we all know to be true.  After all, this stuff has been known for 130 years now. It’s time we proved it.

Tuesday, 3 January 2017

Your New Year's Resolution - Undiagnose a Child This Year

If you’re wondering what to do for your New Year’s resolution, don’t give something up or join a gym.  Neither will work out anyway.  This year, do something truly worthwhile - promise yourself that you will undiagnose a child or three.

Paediatrics is particularly prone to the pitfalls of overdiagnosis and overtreatment.  Although this is a problem, the reasons for overdiagnosis are actually good ones:

When there are no good tests available to tell between two possibilities, we sometimes give a therapeutic trial to help answer the question.  That is a strategy which will lead to misdiagnosis if symptoms improve despite our treatment rather than because of it.

With therapeutic trials, it is often best to challenge the assumption that it was the treatment that worked.   The two best examples that I can think of are childhood asthma and cow’s milk protein allergy in infants.

Let me give you a case to illustrate what I mean:

A 3 month old has been treated unsuccessfully for symptoms of gastro-oesophageal reflux disease (GORD).  A clinician suspects non-IgE Cow’s Milk Protein Allergy (CMPA) because first and second line treatment for GORD has been unsuccessful and because they notice that the baby has quite significant eczema.  (Click here to see a guide to diagnosing feeding problems in this age group)  The clinician decides to trial an extensively hydrolysed feed.  Over the next few weeks, the child’s symptoms of being unsettled and bringing back feeds improve considerably.  The eczema is responding to topical treatment.

In this situation, it is easy to assume that the change of milk was what made the difference.  Often, this is simply confirmation bias.  Colic, reflux and other symptoms of infancy have a tendency to self-resolve.  Of course the treatment may have been what worked but at this point in time, we genuinely have no idea.

This is the time to stop the hydrolysed formula and reintroduce a standard formula.  (Only do this for Non-IgE CMPA.  IgE CMPA is the kind that has urticaria and wheeze etc.  The children with this type of allergy need to be referred to an allergoligist.)   If the original symptoms of being unsettled and vomiting lots return in the next couple of weeks, the diagnosis is now more robust.  If the child remains well despite a return to standard formula, you have undiagnosed a thing.  Marvellous.

The second clinical scenario is the 7 year old with a nuisance cough.  The cough has been there for somewhere around 2-3 months.   There are no associated symptoms such as wheeze or altered exercise tolerance, but the cough is waking the family up at night.  The chest is clear on examination.

So, what is the likely diagnosis?  Surprisingly, in research land, coughs like this turn out to be caused by pertussis infection more often than asthma or reflux disease. (1,2)  It seems that although the pertussis vaccination is successful, infection is still relatively common.  Instead of causing a more significant respiratory illness, what we see in vaccinated children is often just the cough that lasts 100 days.  There are other, similarly benign reasons for chronic cough in children.  Also, there are plenty of significant pathological causes of chronic cough that are not asthma.

Diagnosing ‘cough variant asthma’ is possibly the biggest reason for the current debate about overdiagnosis of asthma in children, fuelled by an article in the BJGP earlier this year. (3)   Many children in the UK are prescribed inhaled steroids for chronic cough symptoms.  If they get better, this is taken as evidence that they had asthma, but there are other possible reasons for this resolution of symptoms.  The evidence suggests that the most likely thing is that the cough has resolved with time rather than with treatment.

This is therefore another opportunity to undiagnose a thing.  As well as stopping inhaled steroids after (Snelson makes up a number quickly…) three months it is probably a good idea to get some sort of objective assessment before, during and after the therapeutic trial.  Peak flows are great if you can get the child to do these well.  In many cases a symptom score (4) is more achievable.  If the only complaint was cough, then a symptom diary is all that is required.

If when you stop the steroids, the child’s cough is still resolved, you have a winner.  Your New Year's resolution is fulfilled.  Of course, once you start, undiagnosing an become a bit addictive.  If you find it becomes a problem, why not join a gym instead?

Edward Snelson

Disclaimer: My New Year's resolution is to get a better disclaimer.

  1. Marchmont et al, Evaluation and Outcome of Young Children With Chronic Cough, Chest Journal, May 2006, Vol 129, No. 5
  2. Wang et al, Whooping cough in school age children presenting with persistent cough in UK primary care after introduction of the preschool pertussis booster vaccination: prospective cohort study, BMJ, 2014;348:g3668
  3. Looijmans-van den Akker et Al, Overdiagnosis of asthma in children in primary care: a retrospective analysis, BJGP, 1 March 2016
  4., Child Asthma Control Test