Childhood Fever – Causes of Fevers in Babies (Infants), Children

A fever in a child (body temperature above 38 degrees Celsius or 100.4 degrees Farenheit), especially in newborn babies, can be a concern for any parent as children often become quite capricious at this time. From a restless sleep to becoming highly irritable and demanding attention, a fever in a child often means a sleepless night for any parent or caregiver. Identifying the cause of the fever is essential as the immature immune system can quickly become overwhelmed with any infectious agent thereby leading to serious complications.

The most common causes of a fever in children include :

  • Infections of the respiratory system, ear, gastrointestinal tract.
  • Teething in babies.
  • After a vaccination.

Febrile Seizures

A febrile seizure (“fever fits”, temperature convulsions) may occur in a child with a temperature above 38.9 degrees Celsius/102 degrees Farenheit. Although a febrile seizure is harmless in most cases, it is distressing for both the parent and child and therefore every effort should be made to control the fever and avoid a seizure.

Newborns and Infants

A body temperature above 38.3 degrees Celsius/101 degrees Farenheit in an infant aged 3 months or younger must always be treated as a medical emergency.

In most cases, a fever is due to an infectious cause. With newborn babies (28 days or younger), there are also other considerations such as perinatal infections. These infections are are acquired in the womb prior to birth, or at the time of birth as a result of passing through the birth canal particularly in an instance where the mother has a sexually transmitted disease (STD) like genital herpes. Due to an underdeveloped immune system at this age, attending to a fever at the earliest possible stage is extremely important.


There is an endless list of causes of fevers in children, most due to infections, but the most common of these include :

Respiratory Tract

  • Symptoms : sneezing, coughing, nasal congestion, inflamed throat (red), nasal tone to voice/cry, difficulty breathing/swallowing.
  • Both upper and lower respiratory tract infections are common in babies and children and are usually due to viruses or bacteria.
  • Many viral infections are generalized although respiratory symptoms may be more prominent. Bacterial infections are more localized.
  • Causes :
    • Viral infections – influenza, respiratory syncytial viral infections (colds, croup), pneumonia, croup, sinusitis. The ‘swine flu’ (H1N1 flu) must also be considered.
    • Bacterial infections – pneumonia, tonsillitis, pharyngitis (strep throat), whooping cough, scarlet fever.


  • Symptoms : diarrhea, vomiting, nausea (upset stomach), lack of appetite, abdominal pain.
  • Cause :
    • Bacterial or viral gastroenteritis


  • Symptoms : ear pain, swollen or red pinna, impaired hearing or even deafness, discharge from ear.
  • Cause :
    • Otitis media


  • Symptoms : child interfering with mouth, toothache, lack of appetite, swelling of cheeks
  • Causes :
    • Gingivostomatitis
    • Dental abscess

Limbs (Legs, Arms)

  • Symptoms : swelling, redness, heat, itching, skin rashes
  • The infection may be of the skin, connective tissue, muscle, bone or joints.
  • Causes :
    • Cellulitis
    • Osteomyelitis
    • Septic arthritis

Urinary Tract

  • Symptoms : frequent urination/reduced urine output (oliguria/anuria) , pain/burning upon urination, blood in the urine, discolored urine.
  • Causes :
    • UTI (urinary tract infections)
    • Kidney infection (pyelonephritis).

Nervous System

  • Symptoms : headaches, stiff neck, intolerance to light (photophobia), irritable, listless.
  • Causes :
    • Meningitis (bacterial/viral)
    • Encephalitis

Childhood Infections

  • Symptoms : Skin rashes (different types) are often the main symptom that alerts a parent to a childhood infection.
  • Causes :
    • Chickenpox
    • Measles
    • Mumps
    • Rubella (German measles)

General Infections

  • Symptoms may be localized to specific systems, generalized or there may be no other symptoms apart from a fever.
  • Causes :
    • HIV
    • Malaria
    • Bacteremia and sepsis, particularly in children younger than 2 years of age.
    • Epstein-Barr virus
    • Cytomegalovirus (CMV)
    • Hepatitis

Other Causes of Raised Body Temperature in Children

  • Teething
  • Vaccinations
  • Drugs, including drug use in mothers who are breastfeeding.
  • Heatstroke
  • Chemical poisoning
  • Cancer
  • Hyperthyroidism
  • Neurological disorders, particularly those affecting the hypothalamus
  • Autoimmune disorders

Related Articles

  1. Baby Fever (Infants, Newborns), Temperature Readings in Children
  2. What is a Fever (Pyrexia)? Normal and High Body Temperature

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