Fever In Children

Fever in children is defined as a rectal temperature of >38°C, oral temperature of > 37.5°C or an axillary temperature of > 37.2° C. Fever less than 41.7°C does not cause brain damage. Only 4% of children with fever develop febrile seizure.

Fever above 41.5°C is called hyperpyrexia and warrants aggressive antipyretic therapy because of risk of irreversible organ damage.

Fever of Unknown Origin (FUO). It is defined as fever of more than three weeks duration, documented fevers above 38.3°C on multiple occasions, and lack of specific diagnosis after 1 week of admission and investigation in a hospital setting.

Nosocomial FUO. This refers to hospitalized patients receiving acute care in whom infection or fever were absent on admission but in whom a fever of 38.3°C or more occurs on several occasions. Multiple readings of more than 38.3°C in a patient with less than 500 neutrophils/mm3 are labeled as neutropenic FUO.Treatment

Documentation of fever

  • Oral temperature is accurate provided no hot/cold drinks have been consumed in preceding 20 minutes. Axillary temperatures are least accurate and rectal thermometers are uncomfortable, especially in older children. Their use should be restricted to children < 6 months.
  • Thermometer must be left in place for 2 minutes for rectal, 3 minutes for oral and 5-6 minutes for recording axillary temperature.
  • Mercury thermometer is accurate and inexpensive. Digital thermometers may measure temperature within 2 seconds and are accurate but expensive. Liquid crystal strips applied to forehead for recording temperature are not accurate.

Find a cause

  • Try to find a focus of infection by careful history and physical examination.
  • Short duration fevers (less than 2 weeks) are usually due to infections. Look for any characteristic feature suggesting involvement of a particular system. Character of the fever (such as relapsing, pel ebstein, step ladder etc) may give a clue to the cause. Heat hyperpyrexia, dehydration fever, allergy to drug (drug fever), and hemolytic crisis are less common causes of short fevers.
  • Long duration fevers lasting more than 2 weeks should be investigated for infections, malignancies, connective tissue disorders, autoimmune diseases and metabolic causes.
  • Appropriate laboratory investigations such as total and differential leucocyte count, peripheral smear, urinalysis, serological tests, radiological investigations, and cultures of blood and body fluids are carried out as indicated by the signs and symptoms related with fever.

Children with any one of the following conditions must be seen immediately:
Age < 3 months old, Fever > 40.6 °C, crying inconsolably, crying when moved/touched, difficult to awaken, neck is stiff, purple/red spots are present on skin, breathing is difficult and does not get better even after clearing of nasal passages, drooling of saliva and inability to swallow, convulsions and looks or acts very sick

Children with any one of the following should be seen as early as possible:

  • Child is 3-6 months old (unless fever occurs within 48 hours after a DPT vaccination and has no other serious symptom), fever>40°C, burning/pain occurs during micturition, fever has been present for >24 hours and then returned and in case of fever present for more than 72 hours.


  • Assure parents and explain that low grade fever need not be treated.
  • Give more fluids.
  • Dress in only one layer of light clothing.
  • Place in a cool and airy environment.
  • Sponging. Sponge with lukewarm water (never alcohol) in children with febrile delirium, febrile seizure, and fever > 41.1°C. Give paracetamol 30 minutes before sponging. Until paracetamol has taken effect, sponging will cause shivering, which may ultimately increase the temperature.
  • Heat stroke requires immediate cold water sponging.
  • The body may be massaged gently so that the cutaneous vessels dilate and body heat is dissipated.
  • For children less than 3 months of age:
    Identify the low risk febrile infant as per Table I. These children can
    be managed on outpatient basis.
    Hospitalize, if appears toxic or does not fulfill the criteria in Table I.

Table I. Identification of febrile infant <3 months of age at low risk for serious bacterial infection.

  1. Non-toxic
  2. Previously healthy
  3. No bacterial focus on examination
  4. Good social status
  5. WBC count 5000-15,000/ml and < 1500 band forms/ ml.
  6. Urine microscopy of centrifuged specimen shows £ 10 pus cells/hpf
  7. If diarrhoea present, stool microscopy reveals <5 pus cells/hpf

In children more than 3 months of age
– Rectal temperature less than 39°C need not be treated. Temperatures higher than 39°C need administration of antipyretics.


Tab/Syr Paracetamol 15 mg/kg/dose, dose can be repeated at 4 hourly
interval (Paracetamol reduces fever by 1-2°C within 2 hours).
Tab/Syr Ibuprofen 10 mg/kg/dose, dose can be repeated at 8 hourly intervals
(Note: Efficacy is similar to paracetamol. Effect lasts for 6-8 hours as compared to 4-6 hours for paracetamol).
Tab/Syr Nimesulide 5 mg/kg/day
(Note: Should only be used in diagnosed fever, since prolonged antipyretic effect may mask the pattern of fever)
(CAUTION: Aspirin should NOT be used for the risk of Reye’s syndrome)
Specific treatment for the cause of safety and fever should be simultaneously undertaken.

Close monitoring of all children, especially young febrile infants, is essential.


  1. Fever. In: Current Pediatric diagnosis and treatment. Hay WW, Hayward AR, Levin MJ, Sandheimer    JM (eds). 15th ed. New York, Lange Medical Books 2001; pp211-212.
  2. Fevers in Childhood. In: Ghai’s Essential Pediatrics. Ghai OP, Gupta P, Paul VK (eds).New Delhi,     Interprint. 2000; pp 175-178.
  3. Fever in the Young Infant. In: Evidence based Pediatrics and Child health. Eds Meyer VA, Elliott EJ,  Davis RL, Gilbert R, Klassen T, Logan S et al. London, BMJ Books 2000; pp 168-177.
  4. Fever Without Focus in the Older Infant. In: Evidence based Pediatrics and Child health. Meyer VA,     Elliott EJ, Davis RL, Gilbert R, Klassen T, Logan S et al (eds),London,     BMJ Books 2000; pp 178-185.
  5. Kramer MS, Shapiro ED. Management of the young febrile child. A commentary on recent practice     guidelines. Pediatrics 1997; 100: 128.