Fever in Children: Recognising the Seriously Ill Child
How to use the NICE NG143 traffic light system to distinguish a self-limiting viral illness from a potentially life-threatening infection in a febrile child, and when to call 999, refer urgently, or safely advise home care.
Why this matters
Most fevers in children under five years are caused by self-limiting viral infections that resolve without treatment. A small but significant minority represent serious bacterial illness, including meningococcal disease, bacterial meningitis, pneumonia, sepsis, or urinary tract infection. The challenge for a community pharmacist is that both presentations can look similar in the early stages, and the window for safe intervention in the serious cases is narrow.
NICE guideline NG143 explicitly acknowledges that community pharmacists work as remote assessors: practitioners whose scope of practice may not include physical examination of a young child. The guidance provides a structured traffic light system (red, amber, and green features) that community pharmacists can apply to a history taken at the counter or by phone. The traffic light framework was reviewed by NICE in April 2025, which confirmed that the system for identifying risk of serious illness remains current and will not be updated.
Several assumptions commonly made by parents and carers are clinically incorrect, and correcting them is part of the pharmacist's role. Antipyretic medicines do not prevent febrile convulsions, so giving paracetamol to ward off a fit is not a reason to use it. The response to paracetamol or ibuprofen tells you nothing about severity: a child with serious bacterial infection may feel and look better an hour after a dose. Aspirin must never be given to children under 16 years because of the risk of Reye's syndrome, a rare but potentially fatal condition causing liver and brain damage.
Age is the single most important variable at the outset. An infant under three months with a temperature of 38 degrees Celsius or above is in the highest risk group regardless of how well they appear. A parent who says their baby does not seem right should be taken seriously. NICE NG143 is unambiguous: reported parental concern about a fever is a valid clinical signal and should not be dismissed.
Red flags vs more likely benign
| Feature | More likely benign | Red flag ⚠ |
|---|---|---|
| Age and temperature | Over 6 months with mild fever; 3 to 6 months with temperature below 39°C; child appears well | Under 3 months with any temperature of 38°C or above: high-risk regardless of appearance (NICE NG143) |
| Skin colour | Normal pink colour in skin, lips, and tongue | Pale, mottled, ashen, or blue-tinged skin, lips, or tongue |
| Rash | No rash; or a blanching rash that disappears completely when pressed with a glass tumbler | Non-blanching rash: rash remains visible under glass pressure; treat as possible meningococcal disease and call 999 |
| Alertness | Responds to parent, smiles or shows social awareness, stays awake, wakes easily | No response to social cues, cannot be roused or will not stay awake, appears ill to an observer |
| Cry | Strong normal cry, or quiet and settled without distress | Weak, high-pitched, continuous, or inconsolable cry |
| Breathing | No reported difficulty; normal effort with no added noise | Grunting; reported rapid or laboured breathing; moderate or severe chest indrawing |
| Fontanelle (infants) | Flat or slightly sunken (very sunken may indicate dehydration) | Bulging fontanelle: possible raised intracranial pressure |
| Neck | Moves neck freely in all directions | Neck stiffness or resistance to moving chin towards chest: possible bacterial meningitis |
| Seizure | No seizure; previous simple febrile convulsion in an otherwise well child is lower risk | Active seizure lasting more than 5 minutes (convulsive status epilepticus) |
Assessing a febrile child at the pharmacy counter: four principles
A community pharmacist cannot perform the vital signs or physical examination that a GP or paediatrician would carry out. The assessment is based on reported symptoms, appearance, and the NICE NG143 traffic light features. Four principles guide the approach.
- Parental concern is a valid clinical signal. NICE NG143 recommendation 1.1.6 states that reported parental concern about a fever should be taken seriously. A parent who says "they're just not right" or "I've never seen them like this before" should be treated as an amber feature, not dismissed. Parents know their child, and a parent who has sought advice repeatedly about the same illness warrants a lower threshold for referral.
- Temperature alone above six months does not predict severity. NICE NG143 recommendation 1.2.11 is clear: in children older than six months, temperature alone should not be used to identify those with serious illness. A child with an otherwise reassuring appearance may still have a self-limiting viral infection even with a high temperature, while a child with a lower temperature but abnormal appearance and behaviour may have a serious illness. Appearance and responsiveness matter far more than the number on the thermometer.
- Do not use temperature response to antipyretics as reassurance. A febrile child who feels better an hour after paracetamol has not been shown to have a non-serious illness. NICE NG143 recommendation 1.4.8 explicitly states that a decrease (or lack of decrease) in temperature after antipyretics must not be used to differentiate serious from non-serious illness.
- Antipyretics and febrile convulsions: a critical misconception to address. Many parents give paracetamol specifically to prevent a febrile fit. NICE NG143 recommendation 1.6.1 states that antipyretic agents do not prevent febrile convulsions and should not be used specifically for this purpose. This is a common belief that pharmacists are well placed to correct.
- Consider sepsis in any febrile child who is rapidly deteriorating. A child who appears to be worsening quickly, is difficult to rouse, has become mottled, or whose parent reports a dramatic and sudden change from normal behaviour should raise immediate concern for sepsis regardless of which specific features are present. NICE NG143 recommendation 1.2.2 advises clinicians to think "Could this be sepsis?" whenever a child with fever has symptoms or signs suggesting possible sepsis.
- Aspirin: never recommended for children under 16. Aspirin is contraindicated in children and young people under 16 years because of the risk of Reye's syndrome, a rare but potentially fatal condition affecting the liver and brain. Paracetamol or ibuprofen, used according to the licensed product instructions and appropriate for the child's age and weight, are the appropriate options. Ibuprofen is not licensed for infants under three months.
If a parent describes a child who is unresponsive, has a non-blanching rash, or has had a seizure lasting more than five minutes, advise 999 immediately without waiting to gather a full history.
The NICE NG143 traffic light system: applying it at the counter
NICE NG143 provides a three-tier traffic light framework for assessing the risk of serious illness in a febrile child. Community pharmacists are explicitly included in section 1.3 as practitioners performing remote assessment. Note that several traffic light criteria involve vital signs (heart rate, respiratory rate, oxygen saturation) that a pharmacist will rarely be able to measure directly. Where these are listed below, they apply when reported by a parent, measured by a colleague with equipment, or visible from observation.
- Red features (high risk): any one red feature indicates high risk and requires urgent action. Features include pale, mottled, ashen, or blue skin or lips; no response to social cues; does not wake or cannot be kept awake; weak, high-pitched, or continuous cry; grunting; respiratory rate above 60 breaths per minute if known; moderate or severe chest indrawing; reduced skin turgor; bulging fontanelle; a temperature of 38°C or above in an infant under three months; a non-blanching rash; neck stiffness; convulsive status epilepticus; focal neurological signs or focal seizures. Immediately life-threatening features (shock, unresponsive, suspected meningococcal disease) require 999. Other red features require face-to-face paediatric assessment within 2 hours.
- Amber features (intermediate risk): these suggest intermediate risk and include pallor reported by a parent; not responding normally to social cues; wakes only with prolonged stimulation; decreased activity; nasal flaring; respiratory rate above 50 breaths per minute in children aged 6 to 12 months or above 40 in children older than 12 months, if known or reported; dry mucous membranes; poor feeding in infants; reduced urine output; a temperature of 39°C or above in a child aged 3 to 6 months; fever lasting 5 days or more; swelling of a limb or joint; not using an extremity or not weight-bearing. Amber features without any red features require face-to-face clinical assessment; urgency depends on clinical judgement and the degree of parental concern.
- Fever lasting 5 days or more: Kawasaki disease. Any child with fever lasting 5 or more days should be assessed by a clinician for Kawasaki disease, a condition causing inflammation of blood vessels that can lead to coronary artery complications if untreated. Additional features may include bilateral red eyes without discharge, cracked lips or strawberry tongue, rash, swelling and redness of the hands and feet, and enlarged neck lymph nodes. These features may not all be present simultaneously and may have appeared and resolved by the time the parent consults. Refer to GP.
- Green features (low risk): normal skin colour; responds to social cues; content or smiles; stays awake or wakes quickly; strong normal cry; normal skin and eyes; moist mucous membranes. Children with green features and none of the amber or red features can be managed at home with safety-netting advice. Safety-netting is not optional: NICE NG143 specifies that parents managed at home must be told clearly when to seek further help.
When a child is brought to the pharmacy counter, look at them first. A child who is alert, smiling, making eye contact, and responding to their parent is providing reassuring information before any questions are asked. A pale, quiet child who does not respond to a parent's voice in a busy pharmacy is a clinical concern.
What to do in pharmacy
Advise parents to: offer regular fluids (breast milk remains the most appropriate fluid for breastfed infants); look for signs of dehydration (sunken eyes, dry mouth, no tears, sunken fontanelle in infants, fewer wet nappies than usual); use paracetamol or ibuprofen if the child appears distressed, according to the licensed product instructions for the child's age; never give aspirin to any child under 16.
Safety-netting: the parent must be told to seek immediate help if any of the following develop: a non-blanching rash, a seizure, the child becomes less responsive or harder to rouse, skin becomes mottled or blue, the child appears to be getting worse, or the parent becomes more worried than they were before. A fever lasting 5 or more days needs GP review to exclude Kawasaki disease. Parental instinct that something is wrong is itself a reason to seek further advice.
Key takeaways
- Any infant under three months with a temperature of 38°C or above is in the NICE NG143 high-risk group regardless of how well they appear. Arrange urgent same-day clinical assessment without exception.
- A non-blanching rash in a febrile child should be treated as possible meningococcal disease and requires an immediate 999 response. Do not wait for other signs to develop or for the rash to spread.
- The response to paracetamol or ibuprofen does not indicate the severity of the illness. Assess appearance and behaviour, not temperature trend. A child who looks better after a dose has not been shown to be safe to manage at home.