The child with a temperature

Practice nurses – whether seeing children in person or undertaking telephone triage – will frequently be confronted with a pyrexial child: how should you assess and manage fever, why does it occur and when should you be worried?

Fever is one of the most common reasons for a child to be taken to see a doctor and is the second most common reason for a child to be admitted to hospital.¹

THERMOREGULATION

Fever is when the body temperature rises above normal. The average normal body temperature taken orally is 36.5°C - 37.2°C. Body temperature is regulated by a temperature control centre in the hypothalamus. This sends signals to the body to raise or lower its temperature. The hypothalamus acts like a thermostat set to about 36.8 °C. This is called the set point.²

Our bodies are typically warmer than the environment anyway. Our body heat is generated by metabolism in the liver, brain, heart, and the skeletal muscles.

In cold conditions skeletal muscles can massively increase heat generation by shivering. Sweat production is decreased, vasoconstriction reduces heat loss through the skin and hairs stand on end, trapping heat. We also alter our behaviour – huddling up to reduce surface heat loss, wearing more clothes and finding heat sources.²

In warm surroundings the body can lose heat by vasodilatation (which makes the skin flushed and warm) and by sweating. Heat radiates off the body – more quickly if we also cool the skin.²

WHAT CAUSES FEVER?

In the presence of infection our immune system produces proteins called pyrogens which raise the set point of our thermostat. The body then adjusts its temperature to obey this new instruction. 3

During the period when the set point of our thermostat is ABOVE the actual core temperature of the body, we raise our temperature by shivering and huddling up. We feel cold. The body is determined to warm up, it’s own thermostat is telling it so.

This is the first phase of fever – the rising temperature. The temperature may rise very quickly, particularly in children, who are capable of particularly high temperatures in response to pyrogens.

Once the set point is reached the temperature may remain high for some time as the immune system fights the infection. Eventually the corner is turned, the levels of pyrogens fall, the thermostat resets downwards and now the patient feels hot. The body sweats and vasodilates and the child throws off the warm blankets.³

The temperature may go up and down just once in an illness – but often it repeats as the immune system produces surges of pyrogens. This is particularly marked in the case of malaria, in which the infecting organism is released into the bloodstream in waves several days apart.

Victorian physicians observed the ‘breaking’ of fever in infections such as pneumonia (the turning point when patient stops shivering and starts to sweat) as a sign that the infection was ‘beaten’ and that recovery was likely.

WHAT IS THE PURPOSE OF A RAISED TEMPERATURE?

Most pathogens reproduce less well if the body temperature rises. A fever is part of our defence.³

Fevers can occasionally, of themselves, have serious consequences (see below). However it is important to be able to explain to parents that raised temperatures in children are not usually dangerous in themselves.

We treat fever because bringing the temperature down does not prevent us from fighting infection. Fevers feel unpleasant and reduce our ability to function efficiently, to eat and drink well and to recover swiftly from our illness.

FEBRILE CONVULSIONS

Many parents fear high temperatures in their children because of the perceived risk of febrile convulsions.

Febrile convulsions occur in susceptible children when the temperature is rising fast, not when it is already high, and a higher temperature does not mean that the child is in greater danger of convulsions

Swinging temperatures may give multiple opportunities for febrile convulsions. Parents of children who experience febrile convulsions should be advised on measures to keep the child’s temperature down.

DIAGNOSING FEVER

Any child presenting to the practice nurse with an illness needs a presumed diagnosis. In the first 48 hours of a fever this will generally be a best guess, open to review and re-evaluation.

In order to make this provisional diagnosis we must:4

• Assess children systematically using history and examination, possibly supplemented by investigations
• Understand and recognise the common patterns of illness
• Recognise deviations from this normal pattern
• Be aware of red flags (see box) and serious or life-threatening conditions
• Safety net and review children who fit the pattern today, but who may not fit it tomorrow
• Be confident in our skills but to know when to seek help
• Not make assumptions or guesses beyond our knowledge or ability

ASSESSING FEVERISH CHILDREN: SPOTTING THE VERY UNWELL

One of the difficulties in assessing children to determine how unwell they are is that the fever itself may cause children to be droopy or floppy, have headaches, nausea or generally look poorly because of the fever and for no other reason.

This is one of the great difficulties in primary care. The practice nurse needs to build a wealth of experience of seeing pyrexial children. Over time it becomes easier to distinguish between a ‘normal’ pyrexial child and one who is unusual. In the meantime do not be afraid to get a second opinion. Every sensibly cautious health professional working in primary care has sought help in these circumstances. Every one of us has sent a child into hospital because they seemed a bit too droopy or sleepy with their fever. It’s better to be cautious than careless. Mistakes happen when we are too proud or nervous to seek help, or when we think that we should already know everything.

Red flags

Red flags which should generate a request for another opinion or admission are given in Box 1. In addition, NICE offers guidance in this area.

NICE recommends a traffic light system to predict the risk of serious illness. Allowance should be made for individual disabilities when assessing learning-disabled children.¹

Table 1 summarises this system.

• If the child has any of the symptoms or signs in the red column they are at high risk of serious illness.
• If the child has any of the symptoms or signs in the amber column, they are at intermediate risk of serious illness.
• Children with symptoms or signs in the green column and none in the red or amber column are at low risk of serious illness. Management of fever should be guided by the level of risk.

Telephone triage

Telephone triage is increasingly a part of primary care in the UK. NICE1 offers some guidance:

• Children with any red features not considered to have an immediate life-threatening illness should be seen within two hours by a healthcare professional.
• Children with any amber features should be seen by a healthcare professional but the assessment of urgency of the appointment is left to the clinical judgment of the assessor.
• Children with only green features can be managed at home with advice for parents and carers, including advice on when to seek further help.

MAKING A DIAGNOSIS

However vague and early the symptoms you need to develop a MOST LIKELY DIAGNOSIS that your examination findings support. You need to rule out, as far as you are able, red flag conditions and then you need to communicate to the parents

• What you think it is
• Why you think this is the diagnosis
• How they should manage the next few days
• What you expect to happen and how you expect it to resolve
• How and when to seek further help
• What red flags should bring them back sooner

COMMON CAUSES OF PYREXIA4

Viral illnesses commonly present early with no other signs. Children are otherwise well and there are no red flags.

The fever associated with minor, self-limiting viral illness usually settles within 48 hours, although some viruses such as roseola cause a more prolonged fever. Following the fever children may develop additional signs and symptoms that assist diagnosis.

Rash is a common feature of viral illness in children. Rashes are seen in conditions such as roseola, Fifth disease, measles, rubella and chicken pox. Infected eczema can also cause a temperature if the infected area is large. The pattern of symptoms and the rash may allow you to make a specific diagnosis.

Tonsillitis, pharyngitis and otitis media are all common viral illnesses in young children. All will cause a fever. This may be prolonged to considerably more than 48 hours if a focus of bacterial infection develops. The symptoms and signs should lead to the diagnosis.

Beware the child who is disproportionately unwell, who cannot open their mouth or swallow saliva. Both quinsy and epiglottitis can present in this way.

Urinary tract infection may present with fever. Children often do not complain of dysuria or loin pain, although nausea and vomiting are common. A urine dipstick is essential in the presence of unexplained fever.

UTI carries a small risk of ascending infection (pyelonephritis). This is greater in children with abnormalities of the renal tract such as urinary reflux. The child is likely to be more unwell with fever and vomiting.

Gastroenteritis is generally obvious by 48 hours. Rotavirus is the most common cause in young children, and causes a prolonged fever, typically for around 5 days, with several days of diarrhea starting on the third day.

RARE CAUSES OF PYREXIA

Meningitis should be considered in any child with a fever and a non-blanching rash, especially if the child looks ill, there are purpuric marks present, capillary refill time is ≥3 seconds or there is neck stiffness. Consider meningitis this if there is fever plus any neck stiffness, bulging fontanelle, decreased consciousness or convulsive status epilepticus.

Septicaemia.Warning signs include:

• Leg pains – which can become severe
• Cold hands or feet – suggesting peripheral shut down
• Pale or mottled skin suggesting poor skin perfusion

In babies an altered cry, irritability, jerky movements, bulging fontanelle and refusal to feed are also warning signs.

Pneumonia: consider if there is fever plus increased respiratory rate. Lower lobe pneumonia can cause abdominal pain.

Septic arthritis and osteomyelitis: consider if there is limb or joint swelling or non-use or non-weight-bearing of an extremity.

Kawasaki disease: consider this if there is fever that has lasted >5 days, plus four of the following:

• Bilateral conjunctival injection.
• Change in mucous membranes in the upper respiratory tract (injected pharynx, dry cracked lips, strawberry tongue).
• Change in the extremities (oedema, erythema, desquamation).
• Polymorphous rash.
• Cervical lymphadenopathy.

CAUSES OF PROLONGED FEVER

Fevers lasting five days or more are unusual. They code as amber on the NICE risk assessment chart and should prompt review of the child and the diagnosis. Fevers that are prolonged or recurrent over several days should prompt a new search for a diagnosis.

Look for a focus of infection, which tends to cause a swinging fever. Common focuses of infection that cause temperatures to persist are the middle ear (otitis media) the urinary bladder (UTI), the throat (tonsillitis) the tummy (gastroenteritis).

Less common sites include joints (septic arthritis), the blood (e.g. malaria) and the brain (meningitis/encephalitis,) or soft tissues (abscess).

Consider unusual but serious conditions which cause prolonged fever, such as Kawasaki disease and tropical infections.

If history and examination do not deliver a definite answer consider referral for further investigation.

MANAGING THE TEMPERATURE4

Once you have a presumed diagnosis then, if you are not worried about the child, they can be sent home with appropriate safety-netting advice.

Tell parents to:

• Use paracetamol or ibuprofen to lower the temperature: it is not now considered advisable to tell parents to use both in combination.
• Do not use ibuprofen in children known to be hypersensitive to non-steroidal anti-inflammatory drugs (NSAIDs), children in whom attacks of asthma have been triggered by an NSAID or children with chickenpox
• Remove clothes from the child to prevent overheating
• Give regular fluids (if breast-feeding then breast milk is best)
• Avoid cold-sponging – no longer advised because the blood vessels under the skin may further vasoconstrict when the temperature is rising, which actually reduces heat loss. Many children will find cold-sponging uncomfortable as they feel cold.
• Monitor for appearance of rash: advise on how to assess a rash
• Get up in the night to check on the child.
• Keep the child away from school or nursery while they have a fever and notify them.
• Seek further help if the child has a fit, develops a non-blanching rash, appears less well, if the fever lasts >5 days, the parent or carer is distressed or if they feel they cannot look after the child.

SUMMARY

Fever is a non-specific sign, and when it presents early in an illness there may be nothing to give the practice nurse a clue as to the cause.

The first task is to assess how ill is the child in front of you. If they are not seriously unwell the second task is to try to determine the likely cause of the fever. Inevitably if the child presents early the range of possibilities will be wide. However the practice nurse using a logical approach to history and examination, with awareness of the NICE guidance on issues of concern, will be able to do this in most cases.

The third task is to remember always to seek help if unsure.

REFERENCES

1. National Institute for Health and Care Excellence (2007) CG160 Feverish illness in children. London: NICE. www.nice.org.uk/guidance/CG160

2. Dabrowski D. Neurophysiology of Thermoregulation http://dwb.unl.edu/teacher/nsf/c01/c01links/www.science.mcmaster.ca/biology/4s03/thermoregulation.html

3. Fever: Medline Plus: http://www.nlm.nih.gov/medlineplus/ency/article/003090.htm

4. Knott L. The Ill and Feverish Child http://www.patient.co.uk/doctor/ill-and-feverish-child