eMedicine Specialties > Emergency Medicine > Pediatric

Pediatrics, Fever

Author: John W Graneto, DO, FACEP, FAAP, Clinical Assistant Professor of Emergency Medicine, Chicago College of Osteopathic Medicine of Midwestern University; Consulting Staff, Department of Emergency Medicine, Swedish Covenant Hospital
Contributor Information and Disclosures

Updated: Aug 6, 2009

Introduction

Background

Pediatric patients presenting in the ED with fever are sometimes the more challenging patients emergency physicians face. Patients with fever can be present in a wide variety of clinical presentations ranging from mild clinical conditions to the most serious of bacterial illnesses. Fever is both a high-impact and a high-frequency chief complaint. The clinician should be knowledgeable about febrile conditions that occur in pediatric patients. Although clinical guidelines have been reported and scrutinized in major journals in the past few years, definitive conclusions are sometimes elusive.¹

Fever phobia is well described as existing with both caregivers as well as medical providers.²

Inconsistent treatment approaches exist even in the most experienced pediatric EDs.³

For related information, see Medscape's Pediatrics Resource Center.

Pathophysiology

A child's core temperature may normally vary by as much as 1-1.5°F throughout the day. This variation occurs with or without pathology being present. An elevated temperature above the normal range is defined as a fever. The standard definition of fever is a rectal temperature of 100.4°F (38.0°C) or higher.

In the face of pathology, pyrogens release prostaglandin E1 and D2. Pyrogens are low-molecular-weight proteins produced by leukocytes.

Prostaglandins mediate the set point for heat regulation in the human body. Their effects act on the hypothalamus and affect the body's response to heat by altering vascular constriction and other heat production and/or release mechanisms.

Frequency

United States

In the general emergency department setting, the chief complaint of fever accounts for approximately 20-25% of the presenting concerns of pediatric patients, with another 10-15% of children having a fever as an associated sign on presentation.

International

International studies both in Europe and Asia show rates of fever similar to US rates in acute care settings.

Mortality/Morbidity

The incidence of serious bacterial illness (SBI) occurs in approximately 1% of children presenting to an acute care setting with fever.

• Serious bacterial infection includes infections causing meningitis, bacteremia or sepsis, enteritis, pneumonia, pericarditis, osteomyelitis, septic arthritis, or cellulitis.^4,5
• Febrile patients may present with other more common bacterial illnesses, such as otitis media, pharyngitis, sinusitis, urinary tract infections, enteritis, and appendicitis, or with viral illnesses, such as upper respiratory infections, bronchiolitis, enteroviral exanthems, gastroenteritis, and flulike illnesses.

Race

No race-based differences are appreciable in the occurrence of fever.

Sex

No sex-based differences are appreciable in the occurrence of fever.

Age

Fevers may occur in any age group. Neonates (<28 d) and young infants (28-60 d) have been traditionally discussed as subsets of pediatric febrile patients. Their presentation and evaluation and management will be the focus of this discussion. Children younger than 24 months of age were traditionally another subset of febrile patients.

• When presenting with fever, neonates and infants are considered at risk for sepsis until proven otherwise. The neonate has been traditionally described as being at greater risk than older children for 2 reasons. First, their bacterial pathogens may be different from those in older children. Their immune systems may be less capable than those of older children to opsonize and compartmentalize infection.
• Note: Not all septic neonates present with fever. Septic neonates may present to the ED with a lower than normal temperature.
• Careful attention to the rectal temperature is suggested in all neonates and young infants presenting in the ED.

Clinical

History

The evaluation of any child in the emergency department should include documentation of the presence or absence of temperature changes.

Thermometer use varies between oral, rectal, or axillary. Ear-probe thermometers may not be as accurate as rectal thermometers in the neonate. Some study results suggest that operator error is the main reason. A rectal-probe thermometer is probably most likely to result in an accurate assessment of a neonate's temperature.

Temperature elevation may not be the only sign of sepsis in neonates and infants. Other potential signs and symptoms of sepsis unique to infancy should also be assessed.

• For the neonate, the history is explored for possible evidence of poor feeding, vomiting, poor social interaction, changes in the quality of crying, and possible apneic episodes. Any of these findings are reasons to consider serious bacterial infection and may warrant laboratory evaluation.
• The birth history is explored to ascertain risk factors for underlying pathology, such as prematurity, maternal infections, and congenital or chronic disease states. Neonates at risk for congenital herpes are those born to mothers with recent genital infection, high-risk sexual activity, and rupture of membranes >6 hours, and scalp electrode. Neonates who present with irritability, seizures, respiratory distress, jaundice, or a characteristic vesicular rash should be considered at risk for neonatal herpes. Note that 10-50% will not develop skin lesions during the course of their illness.
• The history is also explored for previous diagnostic studies and their results.
• For the older child, the following questions might be helpful.
  • What is the timing of the current illness?
  • When did the fever start?
  • How long has the fever been present? Are there any related symptoms?
  • What has been done at home to help control the fever?
  • Has the correct dose of antipyretic been given at home?
  • What is the patients' medical history? The past history may not be applicable in all cases, but it must be explored to reveal potential high risk or complicating factors.
  • Has the child's activity significantly changed during the illness?
  • Is the child tolerating fluids at home? Has there been less interest in eating?
  • What is the patient's immunization status? Which recent immunizations have been administered? Some children may not be fully immunized secondary to compliance, finances, or perceived health risks.⁶
    • See also Complications of routine administration of childhood vaccinations below.
    • In particular, what recent vaccinations might have caused an elevation in the patient's temperature? How many doses of pneumococcal conjugate (PCV-7) vaccine have been administered? How many doses of Haemophilus influenzae type B (HIB) vaccine have been administered?
  • Have the stool patterns changed in consistency or frequency?
  • Has there been recent antibiotic use?
  • Has there been exposure to illness through babysitters, daycare contacts, or other caregivers? Are others at home sick?
  • Have the sleep patterns changed? Has the patient been snoring more at night than usual?
  • Has there been any recent travel that might have exposed the child to illnesses?
• Some pediatric patients may have had a subjective determination of an elevated temperature by their caregivers before coming to the hospital but are afebrile when they present to the ED. Parents may report a temperature elevation in their child without having actually recorded the temperature with a thermometer.
• Parental reporting of fever on the basis of subjective information (eg, touching the child's torso or extremities or feeling his or her forehead) is a reliable indicator of a fever having been present. Studies have shown that the parental assessment of fever in this situation is usually accurate.⁷
• Inquire about the use of antipyretics at home. At times, the clinician finds that the dose of medication used at home is not sufficient. Over-the-counter medications do not always list the correct weight-based dose for children younger than 2 years. Some boxes simply state "call physician" or "seek medical care." Parents should be educated that the ever-changing weight of their child will result in a need to periodically calculate or update the correct dose of medication.^8,9

Physical

The physical examination of the febrile child is directed at locating a source of the temperature elevation, with specific attention to potential serious bacterial illnesses. Hypothermia may be a presenting vital-sign abnormality in septic neonates.

• Observation of the infant or child's interactions with the parent or caregiver is easily done while the history is obtained.
  • What is the quality of the cry? Is it abnormal, high pitched, or weak in effort?
  • Does the child appear fearful of the examiner? Beyond infancy, healthy young children should fear strangers. The child who lies on the examination table without much interaction or who is not disturbed by an examination may be more likely to have a more serious illness.
  • What is the skin color? Are there areas of cyanosis or jaundice? Are there any rashes present?
  • What is the degree of hydration? Are there tears present during crying? Is there moisture on the oral mucosa/lips or tongue? For the neonate, a gentle palpation of the anterior fontanelle may give a general indication to the fluid status. A sunken fontanelle indicates possible hypovolemia/dehydration.
  • What is the response to social overtures? Does the baby smile at the examiner? Does the baby smile or appear interested in a small toy or other shiny object? Social smile remains one of the best predictors of well babies.¹⁰
  • Lethargy is defined as a decrease in the level of consciousness, some examples of which may include the following:
    • Failure of the child to recognize parents or caregivers
    • Absent eye contact with the examiner
    • Failure to interact with the environment at an age-appropriate level
  • Toxicity is defined as a clinical syndrome with the following:
    • Lethargy (see the bullet point above), with,
    • Poor perfusion as evidenced by delayed capillary refill, or,
    • Cyanosis or other signs of respiratory distress
• Physical examination findings suggestive of serious illness (eg, serious bacterial infection) include the following:
  • Presence of dyspnea, tachypnea, grunting, flaring, and retractions should be noted. These findings are abnormal and require further exploration (eg, pulse oximetry, chest radiography).
  • Hydration status should be documented. Specific signs of dehydration might include dry mucous membranes, sunken fontanelle, absence of tears when crying, and/or a lack of urine output (by history).
  • Persistent irritability despite feeding or inability of parents to console the child is concerning. True irritability and lethargy are physical signs traditionally associated with an ill child.
  • The presence or absence of meningeal signs should be documented in older children.
  • Caution: In some infants and younger children (perhaps younger than 12-15 months) who develop meningitis, specific meningeal signs, such as the Kernig or Brudzinski sign, may not be present.
  • A hemorrhagic rash is classically described as resulting from overwhelming systemic bacterial infection due to meningococcemia but may be due to other (usually serious) infections. The presence of petechiae or purpura in febrile children indicates the need for prompt evaluation and therapy.
• Clinical observation scales have been developed to aid in the determination of the degree of illness.¹¹
  • Clinical observation by house staff and seasoned clinicians has produced inconsistent results over the reliability and consistency of clinical observational scales.
  • Regardless of the clinical scale used, one predictor of overall wellness of a child is the presence of a smile.
• A physical finding of an isolated bacterial illness, such as otitis media or pneumonia, should not preclude the clinician from possibly pursuing a more extensive workup to exclude sepsis in the neonate.
• Note: The capillary refill time is generally thought to be the quickest early assessment of hypoperfusion. Faster to obtain than a blood-pressure measurement, the capillary refill time is particularly helpful in a loud or busy ED. Triage nurses should be trained in the rapid assessment of hypoperfusion.
• A delay in the capillary refill time (>2 seconds) indicates hypoperfusion of the skin. Shunting of blood from the capillary beds in the skin is an indication of increased systematic vascular resistance (SVR).
  • An increase in SVR is generally thought to occur early in the face of pediatric hypovolemia. Hypovolemia can result from obvious conditions, such as blood loss and vomiting and diarrhea, or from more subtle reasons, such as tachypnea and sweating.

Causes

Causes of elevated temperature include the following:¹²

• Infectious etiologies (SBI is the concern in the evaluation of the child with fever)
  • Meningitis, or encephalitis
  • Upper respiratory tract infection (URI)
  • Bacterial or viral pneumonia
  • Otitis media
  • Local skin infections, such as cellulitis
  • Oral infections, including pharyngitis due to Streptococcus pyogenes (group A Streptococcus species) and viral herpetic gingivostomatitis
  • Urinary tract infection (UTI)
  • Generalized viral illness
• Parents may be overly concerned about possible outcomes of prolonged high temperature, or they may believe that every fever requires antibiotic therapy.¹³
• The emergency physician may spend time educating parents on these subjects. In fact, not all temperature elevations are caused by bacterial infections. Temperature elevations may occur without infectious etiology.
  • Noninfectious causes of fever include environmental factors, such as the following:
    • High external temperature (especially in the warmer weather months)
    • Over bundling of children in colder weather months
    • Malignancy
    • Rheumatoid diseases
    • Recent immunization administration
• Complications of routine administration of childhood vaccinations carry the risk of temperature elevation as a common adverse effect.
  • Administration of the diphtheria, tetanus, and pertussis (DTP) vaccine may cause fever within a few hours after administration and may persist up to 48 hours.
  • Administration of live-virus vaccinations, such as the measles, mumps, and rubella (MMR) vaccine, may result in temperature elevations up to 7-10 days after its administration.

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