Rashes in children: What is the diagnosis? - Probably a virus

A rash is a very common feature of a paediatric presentation and is often the primary reason for seeking medical advice.

I think that clinicians also sometimes feel a bit of anxiety about rashes.  What does the rash mean?  Should I be able to diagnose the illness based on the rash?

The rash can be diagnostic but often it is not.  Even when the rash gives a specific diagnosis, that diagnosis is usually a virus and treatment remains symptomatic and supportive.

These are some important questions to have answers to when assessing a child with a rash.

• Is the child well? If not, how unwell are we talking about and for how long?
• Is the child febrile?
• How did the rash start?
• How has the rash changed since it started?
• Is the rash itchy?

When examining the child, it is important to avoid the temptation to focus excessively on the rash.  The child should have a systemic examination that will identify any cardio-respiratory, abdominal or neurological abnormality.

The rash itself is then in context of an assessment that has determined whether the child is significantly unwell or has any significant abnormal findings.  What this tells us is whether the rash is of importance because the child is quite unwell, or more of interest since the child is well.  In the well child with no significant abnormal findings, a diagnostic rash can still give useful information in terms of prognostication and the ability to give specific advice about what to do from a infection control point of view.

Let’s look at some specific rash related diagnoses that are accompanied by non-specific symptoms such as pyrexia-

Roseola Infantum

What does it look like?

This infection is most commonly seen between the ages of 6 months and 3 years.  The classical presentation is of a significant fever but a surprisingly well child with non-specific symptoms such as coryza and pharyngitis.  Essentially, the child has all the signs of a viral upper respiratory tract infection (URTI) but with an impressive fever.

A macular patchy erythematous rash often appears as the fever starts to resolve.  Typically the rash is more prominent on the trunk than limbs.

What causes it?

Human herpes virus 6

What specific advice is there for this diagnosis?

None.  Treatment is symptomatic.

Chickenpox

What does it look like?

Chickenpox is a vesicular (small fluid filled lesions) rash which is usually found all over the body.  Children are usually either mildly febrile and unwell in the first few days, or not unwell at all.  The rash is often itchy.

What causes it?

Varicella zoster virus

What specific advice is there for this diagnosis? 

There is no specific treatment.  If the child seems unwell then paracetamol (acetaminophen) is the preferred treatment for systemic symptoms.  While there is some concern about using ibuprofen, the evidence strongly suggests that this concern is unfounded.  However, most children do not become significantly unwell with chickenpox and it is unusual for symptoms to require more than paracetamol.  If a child with chickenpox is very unwell, that is a clinical situation that mandates a careful assessment to consider the possibility of sepsis, usually in the form of invasive streptococcal infection.

Itching can be treated with antihistamines.  In the UK, it is usual practice to ask that the child is kept out of school or nursery until day 7 of the rash, at which point new lesions are not forming and the existing spots are crusting.

Hand, foot and mouth disease

What does it look like?

Vesicles on the face around the mouth, ulcers inside the mouth, vesicles on the hands and feet and perianal vesicles or ulceration.  (Somehow the perianal bit got left out when naming this childhood infection)  The child is usually systemically well but when the rash is appearing may be a little miserable and pyrexial.

What causes it?

Coxackie virus

What specific advice is there for this diagnosis?

Treatment is symptomatic.  This is a good opportunity to practice the philosophy of “treat the child, not the fever.  Many children with hand, foot and mouth disease are not febrile but may be in significant discomfort from the oral lesions.  The importance of analgesia to help the child be comfortable enough to drink should be emphasised.

The UK public health advice for hand, foot and mouth disease is that in itself, it does not mandate and absence from school or nursery.

Pityriasis rosea

What does it look like?

The classical pityriasis rosea rash starts with a herald patch in the form of a well localised erythematous area somewhere, usually on the trunk.  This may go unnoticed and if seen rarely causes alarm.  The generalised rash that follows is what usually leads to the seeking of a medical opinion.  This rash is an impressive patchy pink rash with the pattern of the patches following the lines of the dermatomes of the skin on the trunk, forming what is described as a “Christmas tree” distribution.

What causes it?

Human herpes virus

What specific advice is there for this diagnosis?

The child is usually well at the time of the Christmas tree-like rash appearing so no specific treatment is needed.  It should be explained that the rash may last for a few weeks.  There is no need for the child to be excluded from school or nursery.

Slapped Cheek Syndrome (Fifth Disease)

What does it look like?

Most of the features are non-specific: Fever, coryza, sore throat.  The name comes from the typical bright red rash which appears (usually) on both cheeks.  The redness is both more impressive and more consistent than the flushed cheeks seen in febrile children.  This is often followed by a more non-specific, patchy, popular, blanching erythematous rash on the rest of the body.

What causes it?

Parvovirus

What specific advice is there for this diagnosis?

For the purposes of managing the child, treatment is symptomatic.  Most cases of slapped cheek resolve without complications.

A rare but significant complication of parvovirus is an aplastic crisis secondary to the effect of the virus on the bone marrow.   A history of recent parvovirus infection followed shortly afterwards by significant or atypical illness or pallor should prompt the testing of a full blood count.

Parvovirus infection in pregnancy carries a risk of miscarriage or hydrops fetalis (due to the same aplastic crisis).  Parvovirus is not treatable and most pregnant women are immune.  In most places, the advice for pregnant women who come in contact with parvovirus is to seek medical assessment if they subsequently become ill, especially if they develop a rash of any kind.  If serology confirms parvovirus infection then the pregnant woman should be referred to the fetomaternal team.  Through the marvels of modern medicine, it is now possible to transfuse a baby in utero and potentially keep them well long enough to reach a gestation where it delivery is an option.

Measles 
What does it look like?
Typically the child is febrile, coryzal and coughing for a couple of days before the rash appears.  The rash itself is an erthematous maculopapular rash which usually starts on the head before spreading to the rest of the body.
Kopliks spots are diagnostic but rarely seen as they don't hang around for long.  These are small white spots that appear on the inside of the cheeks, opposite the molars.
Measles should be suspected when a child has significant non-purulent conjunctivitis or is particularly miserable despite analgesia.  Unlike uncomplicated viral illnesses, the child is usually quite unwell several days into the illness when the rash appears. (Consider a differential diagnosis of Kawasaki Disease in the child who has had fever for five days as many of the features overlap.  Unlike Measles, early specific treatment for Kawasaki Disease is essential)

What causes it?

Measles virus

What specific advice is there for this diagnosis?
Measles infection requires specific infection control measures and in the UK is a notifiable disease.  There is no specific treatment for Measles and at presentation, the key decision is about how unwell the patient is.  If well enough to be managed at home, it is very important to avoid unnecessary admission to hospital as this might lead to infection of those most at risk.  However if the child is showing signs of significant infection (mainly encephalitis) then admission is probably necessary.  If referring to secondary care it is essential that the accepting team are aware that Measles is suspected so that the child can be kept away from others from the moment of arrival to hospital.

Viral Urticaria

What does it look like?

It looks like an allergic reaction or nettle sting.  The itchy, raised red and white rash can be seen in any part of the body and can be quite alarming.  Typically this rash appears as the illness is getting better.  Lesions appear and disappear several times a day.  If the onset of the rash is accompanied by other symptoms appearing (such as wheeze, oral swelling or vomiting) then acute IgE mediated allergy should be suspected.  Viral urticarial should not be accompanied by the appearance of these symptoms.

What causes it?

One of many possible viruses

What specific advice is there for this diagnosis?

It should be explained that the rash is caused by the virus and the child’s immune system.  The rash doesn’t tell us anything specific about the infection and doesn’t mean anything bad about the illness or the child.   While anthistamines may reduce the itching, they do not seem to make the rash go away any faster.  The rash will usually resolve spontaneously over the space of several days.

It is notable that children who develop viral urticaria are sometimes taking antibiotics when the rash appears.  This can cause concern regarding possible drug allergy.  The evidence suggests that a large number of children developing rashes while taking antibiotics are simply manifesting a viral rash (including urticaria).  This association is contributing to the overdiagnosis of antibiotic allergy.  Many specialists are now advising that a label of antibiotic allergy is not given to a child if they have an acute illness that could be viral, the only symptom is a rash and it is the first time the child has had a rash while taking antibiotics.

Non-specific Viral Rash

What does it look like?

These rashes can appear during the acute infection or recovery phase of the illness.  Typically the rash is a diffuse, patchy erythema.  It may be macular or papular.  In the majority of cases, all of the rash blanches.  Occasionally, a few petechiae can be found.  In a population vaccinated against most strains of meningococcus, a small number of petechiae is most likely to be part of a viral rash.  Indeed, finding one or two petechiae is within normal for a well child at any point. (1)

What causes it?
Any virus that is on the rash B-team could be responsible.  If it's not a diagnostic rash, you can't make a specific diagnosis.

What specific advice is there for this diagnosis?
It's important to explain that the rash doesn't have any specific meaning. For example, a child with this rash does not need to be kept out of school, for infection control reasons at least. Safety-netting advice should mainly centre around the illness, not the rash.  The rash may well persist after the child's illness has resolved.

Many specific rashes start of as non-specific so if the rash changes significantly they may need to be reassessed.  In particular they should know how to assess for non-blanching rash.

Erythema Multiforme

What does it look like?

As the name (What, no Latin?) suggests, it is a rash with multiple forms.  The rash varies from place to place rather than being uniform in appearance.  The rash varies in appearance and texture.  The typical target lesions that also help make the diagnosis are circular and have a dark red centre.

What causes it?
The rash is in many ways very similar to urticaria in children.  It may be a drug reaction but is more commonly triggered by a virus.  That virus is not usually specifically identified.  Atypical bacterial infection, most commonly mycoplasma, may also trigger erythema multiforme.

What specific advice is there for this diagnosis?
Essentially the same applies to Erythema Multiforme as applies to viral urticaria and non-specific viral rashes.  If there is no obvious specific cause, safety-netting for the illness is most important.

Because Erythema Multiforme can rarely progress to Stevens-Johnson Syndrome, it is worth advising the family to seek reassessment if the child develops an inflamed mouth.

Henoch-Schonlein Purpura (HSP)
What does it look like?The typical HSP rash is a purpuric rash on the lower limbs, predominantly on the buttocks and extensor surfaces.  This is often fully apparent at presentation but sometimes the initial rash is not purpuric.  In some cases other symptoms precede the rash.

Typical symptoms of HSP include leg pains and abdominal pains, though in some cases HSP is asymptomatic.

What causes it?
The cause is unknown, however it is presumed that this vasculitic process is triggered by infection.  In that sense, it can be considered a viral rash.

What specific advice is there for this diagnosis?
Most cases of HSP are suitable for outpatient management and in many cases this is well within the remit of the General Practitioner.  A full explanation of the condition, possible complications and how to manage/ followup can be found here.

Bringing it all together
So there you have it - a reasonably comprehensive list of common rashes seen in childhood infections.  In most cases, the rash will not give a specific cause.  In every case, the clinical condition of the child is by far the more important part of the assessment.  After all, it's probably a virus and you probably can't treat that.

Edward Snelson
Rash decision maker
@sailordoctor

Disclaimer - it might not be.

References

1. Downes AJ, Crossland DS, Mellon AF Prevalence and distribution of petechiae in well babies Archives of Disease in Childhood 2002;86:291-292.

Paediatric Examination by the Book - (Easter egg- When to measure head circumference in a child and what it means)

You know that book that you had when you were learning how to do a clinical examination?  Even books have a teaching style.  Mine was like an old school maths professor.  It taught me that there is only one correct answer and often only one correct way to get to the answer.  And stop doodling Snelson!

If I had owned a paediatric examination text I imagine it would have been more like a literature teacher.  I'm imagining Robin Williams in Dead Poet's Society.  It would teach me that you're never going to approach the same problem the same way twice, and you will probably even find that the answer changes.  Who would like a chocolate?

Having moved from primary to secondary care environments has been an interesting experience.  I recall my first awakening to the differences between two approaches to examination when many years ago I saw a young person with earache.  I was a newly appointed paediatric trainee, but having recently left General Practice I was well accustomed to such presentations.  For reasons I cannot recall, I discussed the case with a consultant and found myself being asked about the systemic examination.  I then had a genuinely useful discussion about what constitutes a full examination.  I had done a detailed throat, ear and neck examination but had absolutely no idea what this young person's spleen was doing that day.  Discuss...

In paediatrics there is no such thing as a routine examination.  This is for several reasons.  Having a routine only works if the same approach works regardless of age or cooperation of the child.  It doesn't.  I am sometimes asked by medical students whether they should be palpating the trachea or percussing the chest of a child.  The obtuse answer is that you should do these things when they are useful and practical.  Often they are not.  If they are, do it.

In any case, examination is normally tailored to the situation.  If a child presents with a finger injury, I presume that the GMC will let me off if I don't check to see if the child has developed a cardiac complication.  Paediatrics is a speciality that quickly teaches you not to think in terms of routine.  Children may have their own opinions about what is about to happen and you often find yourself asking whether something is worth the battle.

General Practitioners have made an art form of the focused examination.  The way that this works is that by the time an examination takes place, the clinician has heard the history and thought about the possible causes of the symptoms in that patient, given their age and past medical history.  What is examined is made up of a selection of what that clinician needs to support or refute each differential diagnosis.

This way of working is very different to the way that hospital medics tend to approach the same problem.  The default in secondary care tends to be a full systemic examination (if that is a thing) in all cases, injury not withstanding.  Each approach has strengths and weaknesses.




























The best approach is probably a combination of the two.  Having a minimum general examination is of value as is the ability to tailor your examination to the patient and the presentation.  There are some elements of examination which are just not part of most peoples routines.  Whatever is left off the "do it every time" list, you need to know and remember when to do it as part of the focused element of an examination.

Let's look at head circumference as an example of something that is routine for some clinicians in secondary care paediatrics but not for most clinicians in primary care or emergency medicine.

How to measure head circumference

Picture credit: https://ftjmikesouth.wordpress.com/

As long as it is done properly, with the correct equipment, measuring head circumference is easy and a more reliable growth parameter than length in babies.  Like any growth parameter, the recorded value is of little use without context.

Head circumference is usually measured either as part of routine monitoring of growth or as part of the assessment of an infant or toddle who has presented with a problem.  In either case, the interpretation of the measurement needs to be in context of a clinical assessment.  The most important elements of this are feeding history, concerns about growth, developmental assessment and neurological examination.

What constitutes abnormal head circumference?

The Great Ormond Street Guide to head circumference (1) suggests the following criteria as abnormal:

• The child’s head circumference measurement indicates excessive or limited growth. 
• Their head is an abnormal shape or size (eg if the measurement falls outside 99.6th or 0.4th centile on the chart. 
• The head circumference is >2 centile lines above or below their height or length measurement. 

What causes abnormal head circumference?

In many cases, HC outside of the 98th or 2nd centile (or where it is disproportionate) is constitutional.  That is to say that it is genetic but without underlying abnormality.  Just as some people are taller or shorter, some people have bigger or smaller heads.  In these cases, there is no other abnormality (including development) and the measurement usually closely follows a centile line.

When do I need to check a head circumference?

Well, if you work in secondary care paediatrics, you may well find that you are supposed to be checking it on all your patients under a certain age.  If that's not you then these are some of the common indications to check:

• Noticeably large or small head
• Growth problems
• Feeding problems
• Vomiting infants
• Any history of symptoms or event with a possible neurological cause (including BRUE/ALTE)
• Developmental concerns or impairment
• Asymetrical head shape
• Child with congenital abnormality of any kind

Why vomiting infants?  It's rare as anything can be but brain tumours can present in babies as vomiting.  Of course, because it is such rare pathology, it is rarely considered early.  Although it is not going to identify a problem very often, checking HC in these babies is harmless and could help to make a diagnosis earlier.

What about the asymmetrical heads?  Positional plagiocephaly is a benign moulding of the skull which is now very commonly seen in infants.

Picture credit: Gzzz https://commons.wikimedia.org/wiki/File:Plagiocephalie.JPG

There was a sharp rise in the incidence of plagiocephaly after the "Back to Sleep" campaign advised to only allow babies to sleep on their backs until old enough to roll over.  This change had a huge impact on the number of cot deaths but it meant that more babies had flattening of the back of their heads, or an asymmetry caused by a tendency to look to one side.

There has been much debate about plagiocephaly treatment but the majority of experts without conflict of interest agree that this is a benign condition (no neurological effects) which tends to improve, if not always completely resolve, as the infant becomes a toddler.

Benign though it is, positional plagiocephaly is common enough to create a risk that craniosynostosis (plagiocephaly's evil twin) might be missed.  Avoid that pitfall by measuring and monitoring the head circumference.  Also check for a ridged suture and a misshaped or small fontanelle.

After making sure that the shape is not due to craniosynostosis, parents can be advised to

• Give the baby time on their tummy when awake
• Change the position of interesting things around the cot.  Alternatively, place the baby's head at the opposite end of the cot on alternate days.
• Alternate the side the baby is held when feeding and carrying
• Consider using a sling to carry the baby instead of being flat in a pram.

But what about the spleen?  Somehow it just doesn't feature in the assessment of positional deformational plagiocephaly as long as craniosynostosis has been ruled out.  What does the book say?  Well, that is a question worth discussing with your literature teacher.

Edward Snelson
Literally not a teacher
@sailordoctor

Disclaimer: I've just realised- I was better at maths than literature.  Ignore everything I've said.  Clearly I'm in the wrong speciality.

References

1. Head circumference: measuring a child, Great Ormond Street Hospital online, downloaded from https://www.gosh.nhs.uk/health-professionals/clinical-guidelines/head-circumference-measuring-child on 24/7/2018

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
@sailordoctor

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.