Fever in children - red flag symptoms

Red flag symptoms to look out for in a child presenting with pyrexia of unknown origin. Plus advice on key questions to ask, examination and investigation, possible causes and when to refer.

Fever in children is a very common presenting problem and the aetiology is generally clear following a detailed history and examination. This article highlights some common red flag symptoms that may warrant further assessment.

Pyrexia (fever) is defined as a temperature >37.2 degrees. A temperature less than 36 degrees should alert the clinician to a possible infection.

Recent NICE guidance has focused on a traffic light scoring system for assessing children under 5.1 It provides some useful tips for GPs to help risk stratify patients, and guidance on when to seek further advice.

Red flag symptoms in younger children (less than 5 years old)

  • Decreased fluid intake
  • Decreased urine output (reduction in wet nappies)
  • Grunting
  • Floppy or irritable
  • Persistent temperature for >5 days despite use of regular antipyretics
  • Increase in respiratory rate, subcostal or intercostal recession
  • Non-blanching petechial rash
  • Cool peripheries
  • Increased smelly urine
  • Bulging fontanelle
  • Reduced interest in external stimuli
  • New onset seizures
  • Complicated birth or requirement for special care baby unit

Red flag symptoms in older children

  • New onset headache with or without neurological symptoms
  • New onset seizures
  • New onset rash particularly if non blanching
  • New onset vomiting
  • Bloody diarrhoea
  • New onset abdominal pain
  • New onset joint swelling or pain
  • New onset facial swelling
  • New onset back pain (thoracic or lumbar)
  • New onset limp
  • New onset sore throat, otalgia, ear discharge
  • Photophobia +/- neck stiffness
  • New onset vaginal discharge
  • New onset testicular swelling with or without erythema
  • New onset dysuria, urinary frequency or haematuria
  • Unexplained persistent weight loss
  • Persistent neck +/- groin lumps, axillary lumps
  • Any recent foreign travel
  • Any history of persistent night sweats (> 6 weeks)
  • Any new onset cough, shortness of breath, expectorate, chest pain
  • Persistent fever for > 1 week with no clear cause

The red flags listed for older children may also apply to younger children under the age of 5.


Common childhood illnesses include chickenpox, croup, URTIs, otitis media, otitis externa, and tonsillitis.

Rarer illnesses causing rash include measles, slapped cheek syndrome, kawasaki disease.

Acute respiratory causes include bronchitis, whooping cough, and pneumonia. Chronic respiratory causes include TB.

Consider other ENT infections such as quinsy, glandular fever and, rarely, mastoiditis. Other possible causes include:

  • Dental infection
  • Mesenteric adenitis
  • Cerebral infection such as meningitis
  • GI infections that could be either bacterial or viral
  • Pyloric stenosis
  • Intussusception
  • Tropical diseases such as malaria, dengue, Lyme disease
  • Appendicitis
  • Testicular or ovarian torsion
  • Septic joint
  • Juvenile arthritis
  • Pelvic inflammatory disease
  • Ankylosing spondylitis
  • Urinary tract infection, complicated or uncomplicated
  • Endocarditis
  • HIV infection
  • Haematological malignancy
  • Cellulitis or any origin
  • Intra-abdominal collections such as appendix or pelvic collection

Centor criteria

Centor criteria provide a helpful guide when making a decision on antibiotic prescribing for common RTIs and ENT infections.2 The four Centor criteria are:

  • Presence of tonsillar exudate
  • Presence of tender anterior cervical lymphadenopathy or lymphadenitis
  • History of fever
  • Absence of cough

The presence of three or four of these clinical signs (Centor score 3 or 4) suggests that the person may have GABHS (40–60% chance) and may benefit from antibiotic treatment.

The absence of three or four of these signs suggests that the person is unlikely to have an infection (80% chance), and antibiotic treatment is unlikely to be necessary.

Important! Antibiotic treatment is unlikely to be necessary if only one Centor sign is present

Taking a history

GPs see children of all ages right the way through from neonate to early adulthood. How these children present varies and in the younger age group, a third party history is generally required. However, try and gather as much information from the child as possible.

Parental/guardian concern will play a big part in how you manage the case so be alert to the parents’ or guardians’ ideas, concerns and expectations. If the child is able, they will often have their own fears and beliefs that may need exploring.

The history will differ slightly depending on the age of the child and should include the following. Some of the following questions will apply to younger infants and not older ones.

  • How long has the child had the fever?
  • What do the parents/guardians mean by fever?
  • Have they measured it and if so, how? What results have they obtained?
  • How has the child/young adult been since the fever started?
  • Are they playing normally if relevant?
  • Are they responding normally?
  • Are they more drowsy?
  • Are they passing urine? You may wish to enquire about wet nappies if relevant?
  • Are they eating and drinking as normal? If not, is there an obvious reason for this
  • Do their extremities (hands and feet) feel warm or cold?
  • Has the patient developed a rash? If so, explore this further and take a more detailed history
  • Are the child immunisations up to date?
  • Was the birthing process normal? Did they require any special care involvement? If so why? Were there any antenatal problems?
  • Any history of foreign travel?

Specific questions

Once you have accurately painted a picture of how the child has been since the onset of the fever, if not already clear from observation and the opening statement, ask more specific questions. You may need to do a full systems review if the problem continues to remain unclear.

Detailed review of the following systems may be required and any positive symptoms may require further evaluation.

  • Neurological system: any history of headaches, vomiting, or weakness of the arm, face or leg?
  • Respiratory system: any cough, expectorate, shortness of breath or pleuritic chest pain?
  • ENT system: any history of otalgia, otorrhoea, coryza, sore throat? Any dental problems reported?
  • Gastrointestinal system: any history of diarrhoea, vomiting, or abdominal pain? New onset testicular swelling may be relevant in young males.
  • Dermatological history: has there been a rash and if so, where and how has this changed over time? Does it disappear with pressure? Has there been any changes to any washing powders, detergents or conditioners? Is there a dermatological history that needs to be considered?
  • Cardiovascular system: has there been a history of exertional chest pain, shortness of breath, palpitations or syncopal episodes?
  • Musculoskeletal system: is there any history of joint pain, swelling or limp? Is there any new onset lumbar or thoracic back pain?
  • Gynaecological history may be relevant so a sensitive approach may be required here. Has there been any new discharge? Is there a chance of pregnancy? Is there any inter-menstrual bleeding?
  • Urological history: has there been any dysuria, urinary frequency, loin pain or haematuria? Has there been a change to the smell of the urine?


This will vary depending on the age of the child. Younger children are likely to require a more detailed assessment due to symptoms being more non specific. Infants should be undressed and the following examined.

  • Temperature - tympanic or axillary using an electronic thermometer
  • General appearance - are they pale, floppy, irritable, clingy?
  • Respiratory rate
  • Heart rate
  • Capillary refill time (CRT)
  • Warm or cool peripheries
  • Any obvious rash. Does this blanch?
  • Fontanelle - does this appear to bulge?
  • ENT system
  • Cardiovascular system
  • Gastrointestinal system
  • Respiratory system
  • Palpate for lymph nodes.

Older children where a history is more likely, will allow you to focus your examination more.

Have a summary sheet of vital signs for different ages as they vary dependent on age.3


These will be guided by your history and examination but could include:

  • Some routine blood work such as FBC, U&Es, CRP, IM screen
  • Plain chest film
  • Urinanalysis - the age of child will determine if a nappy sample is required or a standard MSU can be obtained
  • Throat swab
  • Ear swab
  • Wound swab if relevant
  • Genital swabs if relevant

When to refer

Decisions to refer will be made after a complex assessment including history, examination, experience and in this scenario, the level of parental concern. The NICE traffic light scoring system also provides a useful guide of symptoms and signs that may aid the decision making process.

Refer when:

  • Fever is persistent > 5 days despite antipyretics, and there is no clear cause
  • There is a non-blanching rash
  • Diagnosis is not clear from the history and examination and the child is unwell
  • You suspect septic shock
  • You suspect meningococcal septicaemia

Consider referral if there are:

  • Concerning features on examination
  • Concerning features in the history as per the red flags above.

Clinical experience will often dictate referrals in the context of a pyrexial child.

If you decide to send patient home then ensure detailed safety netting. You can provide the patient with a leaflet or signpost patient information.

  • Dr Singh is a GP in Northumberland

Take a test on this article and claim your certificate on MIMS Learning


  1. NICE Fever in under 5s: assessment and initial management. CG160. May 2013.
  2. CKS Sore throat - acute. Scenario - management. July 2015.
  3. Charbek E Normal vital signs. Medscape August 27 2015
Key learning points
  • Pyrexia (fever) is defined as a temperature >37.2 degrees
  • Common childhood illnesses include chickenpox, croup, URTIs, otitis media, otitis externa, and tonsillitis.
  • Consider ENT infections such as quinsy, glandular fever and, rarely, mastoiditis
  • Parental/guardian concern will play a big part in how you manage the case
  • If you decide to send patient home then ensure detailed safety netting

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