Friday, 27 November 2015

Fairy logic - how to avoid the understanding gap

I recently realised that my medical advice is not as good as it could be.  I tell parents and young people what will help their treatment have the maximum chance of success, but I do so without always thinking about how the advice might fall into an understanding gap.  From now on I am going to try to apply fairy logic whenever I give my explanation of what to do next.

Fairy logic?  Let me explain: In popular mythology, fairies are often need permission from people to do things.  As a result they look for opportunities to interpret what is said to them in inventive ways.  For example if a fairy wants to enter your abode, they need permission.  If they are told, "You can't come in my house" they may see the loophole and go into the garage instead.  In consultations, I think that this misunderstanding of convenience happens often, albeit unintentionally.

For example, with eczema treatment, I will advise that soap should be avoided.  I should probably include shampoo and shower gel in that to avoid misinterpretation.

Other examples include

  • "Stopping milk" when cow's milk protein allergy is suspected (should be stopping milk and anything containing milk, milk products like cheese or having these as an ingredient)
  • "Smoking in the house is associated with chest problems in children" (should be that having a smoker who lives in the house is associated with chest problems in children.  Avoiding smoking in the house and car is good, but quitting is better.)

I know that time is at a premium when there are lots of patients to be seen.  However to avoid that misinterpretation you have to be specific and be comprehensive.  If you have examples of circumstances which benefit from this, why not post them in the comments section?  I suspect that there will be plenty of times that I am not aware of when I need to apply fairy logic to avoid the gap.

Edward Snelson

Disclaimer: I am largely basing my knowledge of fairies and their way of thinking on the writings of Eoin Colfer, but I'm not even sure he's ever really met a fairy.

Friday, 20 November 2015

Outside-in or Inside-out? Top tips for making childhood eczema better

In developed countries the incidence of eczema has been increasing for several decades.  At the same time, children are tending to take longer to grow out of having eczema, leading to an even greater prevalence.  While it can be difficult to treat in a General Practice setting, eczema treatment is ripe for Primary Care expertise to make a big difference to a group of children who have an unpleasant but treatable condition.

Recently, I heard an experienced paediatric dermatologist try to squeeze all his eczema wisdom into about an hour long session.   What I learned was that by understanding the way that eczema works, I can be better at treating eczema.

There are many proposed models for what causes and perpetuates eczema.  Two of these are the ‘inside out’ and the ‘outside in’ models.  If you are interested in these things, there is much debate about whether eczema is caused by allergy and perpetuated by damaged skin versus being caused by a defective skin barrier which then leads to allergens penetrating the epidermis.  If you don’t care and just want to treat the eczema effectively, the answer is simple: do something about all the factors involved regardless of which is chicken or egg.
Here's how to do that:

1. Restoring the skin barrier
Think of the epidermis as being a brick wall.  In eczema all the mortar is falling apart and there are gaps between the bricks.  That means that the wall is leaky and does not protect the house from the elements.  What is needed is to repair the mortar.  In eczema, repairing the skin barrier requires oil.  This can be achieved in several ways.  The first thing that is needed is to use emollients. 

Of course there are many emollients available.  Whatever the treatment is, it needs to be one that the family will use often enough.  This requires the provision of large amounts so that the parents will be liberal in using it.  They need to be told to apply it often enough to keep the skin feeling greasy all the time.  Some creams are greasier than others.  Bigger is not always better though.  Sometimes families find the greasiest creams to be too oily and so they apply them less often.  It is important to make sure that they are happy with the cream prescribed.

As well as replacing oils, we need to make sure that whatever is there is not being taken away.  Soaps, shampoos and detergents need to be avoided.   Instead, encourage the use of water alone or with bath oils.  Aqueous cream contains sodium lauryl sulfate which is a mild detergent.  Aqueous cream should not be used as an emollient but can be used as hand soap (1).

2. Treating the inflammation
Returning to the inside out/ outside in way of thinking about eczema, restoring the barrier is not going to be effective on its own when there is inflammation present.  Inflammation requires steroid creams.  How strong a cream and how long it should be given depends on the severity of the eczema and how well it responds.  In short, the steroid cream should be prescribed at a strength that treats the eczema and for as long as necessary to resolve the inflamed skin.  It is very important to attack the eczema from every other angle at the same time so that the steroid cream is given the best possible chance to work and be stopped.

3. Addressing the itch
Treating eczema does not stop at using emollients and steroids.  The next issue to consider is the itch-scratch cycle.  Inflamed skin is itchy and scratched skin makes eczema worse.  Antihistamines can make a big difference during an exacerbation of eczema, not just to help with symptoms but also to speed recovery.

4. Treating drivers of inflammation
Another consideration is the possibility of something driving the inflammation.  Bacterial infection may be manifested as exudative or golden crusted areas.   Herpes virus infection will usually be evident either by the characteristic vesicles or the ulcerated lesions left behind.  Treatment of bacterial infection with oral antibiotics is sometimes needed.   Topical treatment with fucidic acid cream is often the preferred option.  Topical antibiotics must not be continued long term as this simply promotes resistant bacteria colonising the skin. 

Besides infection, there may be allergens that are identifiable.  Avoiding (e.g. specific foods) or minimising (e.g. house dust mite) these precipitants is important, though often difficult.

Having this four pronged approach is much more likely to be effective than being overly simplistic such as by just prescribing a steroid cream for a flare up of eczema.  Good explanation of the treatment and being supportive are both essential to the success of any plan.

I am told by paediatric dermatologists that they often don't use special secondary care treatments when they see children with eczema.  What they do is to use the same treatment that are available in primary care but use these treatments differently.  That sounds like an opportunity for us to make these dermatologists a bit more redundant.

Edward Snelson

Disclaimer: Other models of eczema pathogenesis are also available


  1. National Eczema society - "Why Aqueous Cream is Bad for Eczema"
  2. Drug Safety update - aqueous cream may cause irritation

Saturday, 14 November 2015

When it walks like a duck- Do I give salbutamol to this 11 month old?

This year saw the arrival of the NICE Bronchiolitis guidelines.  Like many guidelines, this requires the clinician to know that the problem that the child has is bronchiolitis. The trouble is that there are times when there is uncertainty.  It is an important distinction to make since bronchiolitis is best left well alone.  You should not prescribe inhalers, antibiotics or steroids.  Viral wheeze on the other hand requires the liberal use of inhalers for appropriate to the severity of the exacerbation.

As a medical student I was taught that beta-agonists such as salbutamol don't tend to work under the age of one.  That is only partly true.  Beta-agonists don't work for bronchiolitis and most children under 12 months with wheeze have bronchiolitis.  However when the problem is a viral induced wheeze the inhaled Beta agonist is exactly what is needed even if they child is below a year old.

Bronchiolitis and viral induced wheeze have a similar presentation but very different mechanisms which is why one responds and the other doesn't.  Bronchiolitis is essentially a problem of wetness.  The viral lower respiratory tract infection causes the airways to be constricted by the accumulation of secretions.  With viral induced wheeze, the infection has induced bronchospasm.

In both cases there will be a cough, coryza, wheeze and possibly some respiratory distress.  Only one needs inhalers or nebulisers to be given.  So how do I tell them apart?

The easiest way is to look at the child's age.  There seems to be a fairly good split between the typical age groups of the two conditions.  Bronchiolitis tends to affect those under 12 months old while viral induced wheeze tend to be seen in the over 12 month olds.  Using that as a cut off will leave you being correct a lot of the time.  Of course there are exceptions and they will usually be those children a few weeks or a couple of months either side of that cut off.

So for those who are well before their first birthday you can assume they have bronchiolitis.  If the child has already started to outgrow the clothes that they were given for their first birthday, you can assume they have a viral induced wheeze.  But what about the ones who are too close to call?

One thing that helps is the prodrome.  Typically, children with bronchiolitis have a few days of being snotty before the cough develops.  Then there is a daily worsening of cough followed by feeding difficulties.  By day 3 of the cough there may be fast breathing and an audible wheeze.

With viral induced wheeze there is a variable length of coryzal illness from a day to a week.  What is noticeably different is the onset of the wheeze and respiratory distress.  This will usually happen over the space of hours, not days.

The other factor that helps is the severity of the symptoms.  Consider our 11 month old with wheeze: If bronchiolitis affects children from birth to about 15 months of age, the most severely affected will be the littlest babies.  Wet lungs when you are a few weeks old is no walk in the park.  So by the time you are 11 months old, bronchiolitis is less likely to be severe.

Why not just try inhalers with all wheezers?  The answer is that it is possible that this might make the child worse.

If an infant has bronchiolitis, they fight the good fight against wet lungs.  They succeed against the odds since they are less able too feed and use more energy in the effort of breathing.  What we must do as clinicians is avoid making this worse.  Don't give unnecessary antibiotics that will fill and irritate their stomachs.  Don't send them home with ineffective inhalers which will result in a routine of upsetting and tiring out the child.

Conversely, make sure that children with viral induced wheeze get enough beta-agonist.  This might be quite a lot (the salbutamol paradox).

So, because it is an important distinction, use age, then prodrome and then severity in that order to decide if it is bronchiolitis or viral induced wheeze.

Edward Snelson

Wednesday, 4 November 2015

Hot topic - Should children who develop a rash while taking antibiotics be re-challenged in primary care?

These are the facts:

  • The vast majority of children who have been labelled as allergic to penicillin have no evidence of allergy on patch-testing, prick testing or oral challenge.  
  • The most common cause of acute urticaria in childhood is viral illness.
  • For various reasons, many children are prescribed antibiotics for viral illnesses.  During the time that they are taking antibiotics they may develop a  rash (urticarial or non-specific) which might lead to the conclusion that the child is reacting to the antibiotics when in fact the rash is due to the viral illness.
  • Anaphylaxis kills around 20 people per year in the United Kingdom.

In this post I would like to debate the pros and cons of what should happen next when a child has been labelled as allergic to penicillin.

The clinical scenario is this: While taking penicillin for an upper respiratory tact infection, a child develops an urticarial rash.  There are no other symptoms such as wheeze associated with the onset of the rash.  The rash settled after a few days.  The child has been labelled as penicillin allergic on the basis of this episode.
The child then presents three months later with an acute otitis media and fulfils the criteria for a prescription of amoxicillin.  What should you do?

One option is to prescribe an alternative antibiotic.  The argument for this is that there is a possibility that the urticaria was due to the penicillin.  Why take a risk?  Although the likelihood of a further reaction is small there is such a thing as penicillin allergy.  Furthermore the child could have a more significant reaction this time.  They could have an anaphylaxis or develop Stevens-Johnson syndrome.  Despite the small chances, the potential severity of the possible reaction makes avoidance of penicillin the best way forward.

The second option is to prescribe amoxicillin.  The attribution of the label 'allergic to penicillin' was not justified.  The vast majority of children who develop an acute episode of urticaria do so in response to the viral illness.  If anything, the appearance of such a rash probably indicates that the antibiotics were unnecessary rather than problematic.  Research has shown that only about 1 in 20 children labelled as allergic to penicillin actually have evidence of a reaction.  Furthermore, the fear of a more severe reaction is probably unfounded.  The only factors known to increase the severity of an allergic reaction are dose and route.  So if the same dose and route are used, the worst that should happen is a recurrence of the rash.  When compared to the increased probability of side effects with an alternative antibiotic, prescribing amoxicillin is the least harmful option.  It is simply a question of amoxicillin being the best drug for the job.

The third option is to prescribe amoxicillin but to have them take the first dose in your clinical setting and wait for up to an hour before leaving.  If the child has a label of penicillin allergy which we know is likely to be wrong, this option somewhat addresses the issues of having been told that they are allergic to penicillin.  The parents are likely to be anxious about giving the medicine.  If there is a reaction to the medicine then this can be assessed as it occurs so that there is no future doubt.  In most cases the reaction will again be mild.  If respiratory or systemic features occur then all of the drugs needed for the initial treatment of allergy and anaphylaxis can be given in Primary care.  In short, it is unlikely that a reaction will occur.  If it does it can be assessed.  It is very unlikely that the reaction will be anaphylaxis but if that occurs it can be treated and the child sent immediately to secondary care by ambulance.

So having heard the arguments, what do you think?  It's time to choose.  Here is the link to the poll: Click here
Alternatively you can join the debate and post a comment below.

Edward Snelson

Disclaimer:  I never prescribe antibiotics.  I use antibionics (much stronger)


  1. The role of penicillin in benign skin rashes in childhood: a prospective study based on drug rechallenge, J Allergy Clin Immunol. 2011 Jan;127(1):218-22
  2. Penicillin Allergy in Children  Current Allergy & Clinical Immunology, June 2009 Vol 22, No. 2