Fever

Introduction

Fever is one of the most common chief complaints of children presenting to the emergency department accounting for 20% of all pediatric ED visits.  Thus a general understanding in the management of these patients is crucial for all emergency medicine clinicians.

Initial Actions and Primary Survey

Initial Actions

General Impression:

1. The first step to any child presenting to the emergency department is to recognize the unstable patient. A quick visual and auditory assessment should be done before even touching the patient.
2. First, consider their appearance: is the patient moving and interacting with good muscle tone? Is she consolable? Does she look at you or have a blank, glassy-eyed stare? Does she have a weak or strong cry?
3. Next, consider work of breathing: do you hear snoring, hoarse speech, stridor, grunting or wheezing? Abnormal airway sounds provide crucial information about breathing effort and anatomical location of the breathing problem. Do you see signs of respiratory distress such as assuming the sniffing or tripod positions, head bobbing (in infants), nasal flaring or retractions?
4. Finally, check skin as a quick assessment of circulation and cardiac output. As cardiac output decreases, the body will compensate by shunting blood flow from non-essential organs (such as skin) to maintain perfusion to the heart, brain and kidneys.  Any white, patchy or blue (pallor, mottling, cyanosis) skin should be a quick indicator that circulation needs to be quickly addressed.

By routinely checking the appearance, work of breathing and skin upon each pediatric patient encounter, the clinician will be able to quickly assess the patient’s physiologic status, be able to prioritize their management efforts and provide prompt interventions when abnormalities are noted. Positive finds plus history or vitals revealing fever puts this patient at higher risk for having a serious bacterial infection (SBI) and will dictate a more aggressive approach to our pediatric febrile patient.

Primary Survey

 Any patients noted to have abnormalities in the general impression will benefit from a step-wise primary assessment of airway, breathing, circulation, disability and exposure, a careful review of vital signs and a thorough physical examination.

Risk stratification:

In an otherwise well appearing or stable febrile child, the physician’s primary task is to determine if their fever is due to a SBI or not.  This may be difficult, especially in the younger infant. In fact, a normal physical examination can provide false reassurance to a clinician in a young infant.

Pertinent questions when inquiring about the patient’s history include sick contacts, recent antibiotic use, immunization status, and environmental, animal and travel exposures.  In addition to asking about the duration, timing and degree of fever, localizing symptoms can often clue the clinician towards a more definitive diagnosis.  In infants, many times the only signs of disease may be changes in feeding, activity, and urine and bowel habits. Questions regarding birth history (especially prematurity), prolonged rupture of membranes, low birth weight, and maternal infection may help identify higher risk neonates.

Special populations must also be considered when determining who is high risk. These include patients with cancer, AIDS, sickle cell disease, congenital heart disease, indwelling devices (such as VP shunts) and immunosuppression.  These conditions may hinder normal immunologic responses and predispose to diseases and infections that would otherwise not be harmful. These patients should be evaluated as “high risk” despite a benign presentation.

PEARL: Whether or not the fever was lowered after administration of an antipyretic medication has no predictive value to determine severity of the infection.

Consider the age of the patient, the younger the child, the higher the risk of life-threatening illness.   An otherwise healthy neonate that presents with fever has a one in ten chance of having a serious bacterial illness, whereas that risk decreases significantly to approximately one in 1000 in the six month old.

Fever is further classified based on age group when determining which child needs further evaluation, using the following rectal temperatures:

• 0 days – 3 months:      Fever of > 38.0 ºC (100.4 ºF)
• 3 months – 3 years:     Fever of > 39.0 ºC (102.2 ºF)
• 3 years and older:       Fever of ≥ 39.5 ºC (103.1ºF)

While little disagreement exists regarding the management of neonates younger than 28 days, considerable disagreement and practice variation exists for children 29 days to 36 months of age.  In children more than 36 months old there are more reliable clinical findings and greater agreement among practitioners.  Regardless of age, any ill appearing child with fever should have a complete sepsis evaluation and be admitted to the hospital on IV antibiotics.

0-28 days

An aggressive approach is indicated for any temperature above 38°C, even in a well appearing child. Obtain IV access, CBC, CMP, catheterized urinalysis with urine culture, lumbar puncture (cell count and differential, culture, protein, glucose, CSF-PCR for herpes and enterovirus) and blood cultures.  Start empiric antibiotics (ampicillin plus gentamicin or cefotaxime), specifically targeting Group B Streptococcus, E. coli and L. monocytogenes. While it is not recommended that every neonate that undergoes a lumbar puncture be worked up for HSV, there are certain criteria that would indicate HSV testing.  These include: seizure activity, bloody tap (especially with a mononuclear CSF pleocytosis), afebrile septic-appearing infant, elevated serum transaminases, maternal genital herpes, and those with a rash consistent with HSV.  In neonates with risk factors for HSV, acyclovir should be started in addition to the antibiotics.

PEARL: Note that for any ill appearing infant the workup is the same as for the neonate, although the choice of antibiotics may differ slightly. The following recommendations are for an otherwise well appearing child with fever.

29-60 days

A minimum of a CBC, catheterized urinalysis with culture and blood cultures are needed.  Many experts recommend routine lumbar puncture as well.  Chest x-ray and stool studies should be ordered based on history of cough, respiratory distress or bloody diarrhea and physical exam.  A basic guideline is to admit the patient for any positive results in the workup or inability to follow-up and begin ceftriaxone.  If the workup is completely negative, the physician may discharge without antibiotics and follow-up the next day.  If the patient is placed on empiric antibiotics, a lumbar puncture should be performed.

61-90 days

Start with CBC and catheterized urinalysis and urine and blood cultures for fever over 39.0°C.  Chest x-ray is indicated with any respiratory symptoms.  If the WBC is not elevated and the UA is normal, empiric antibiotics are not required and the patient may follow-up the next day. If the temp is <39.0°C in an otherwise well appearing child, no lab work is needed if next-day follow-up is possible. If the UA is abnormal, treat with ceftriaxone. If just the CBC is abnormal, LP should be considered and empiric ceftriaxone initiated.

PEARL: The approach to the 1 – 3 month old child is controversial.  An abnormal WBC count is considered to be greater than 15,000 or less than 5,000.

3 months – 3 years

The following questions should be considered: Is the fever > 39.0°C? If no, treat with antipyretics and diagnostic testing as per clinical judgment.  If yes, did the patient receive their scheduled 2, 4 and 6 months immunizations? If yes – consider urinalysis/urine culture and chest x-ray if they have respiratory symptoms. If no, consider CBC, blood culture, urinalysis/urine culture.  Consider empiric antibiotics for WBC > 15,000 and a chest x-ray for WBC > 20,000.

PEARL: The probability of a febrile male between 3-24 months without urinary tract abnormalities having a UTI is about 6% in the uncircumcised and 1% in the circumcised.

>3 years

The risk of occult bacteremia is very low.  Look for localizing signs of infection.  The key to ruling out life-threatening illness is a thorough history and physical exam.  Remember that meningococcal infection is bimodal in age distribution, and adolescents should be evaluated for headache, stiff neck, altered mental status or petechiae. A child with fever of unknown etiology and new onset neutropenia should be considered for cancers, especially leukemia.

*CBC=complete blood count, UA=urinalysis, LP= lumbar puncture, CXR, chest x-ray, IM=immunizations, WBC=White Blood Cell Count

Note that while rapid testing for viral etiology can help diagnose frequent causes of infection such as influenza and RSV, it is not useful when ruling out the simultaneous presence of bacterial infections, especially in the very young.

C-reactive protein (CRP) is an acute phase protein that forms approximately 6 hours after the beginning of an infection and peaks around 36 hours.  Some studies show that CRP may help distinguish between a viral and bacterial infection early in the course of illness.  Other early-phase reactants are being studied, but are not yet commonly used in fever workups.

Differential Diagnosis

Infections (most are self-limiting viral illnesses. UTI is the most common cause of bacterial infection in pediatrics):

• Serious Bacterial infection
• Croup: 6 mo – 6 years
• Bronchiolitis: < 2 years, 70% caused by RSV, the leading cause of hospitalization in infants and young children
• Pneumonia
• Otitis Media: common at 6 – 18 months
• Pharyngitis
• Gastroenteritis
• Gingivostomatitis
• Viral exanthems
• Soft tissue & skin infection
• Sinusitis
• Excessive clothing and ambient hyperthermia (bundling): seen in young infants
• Medication side effects or overdoses
• Central nervous system abnormalities
• Trauma
• Collagen vascular disorders (systemic lupus erythematosus, juvenile idiopathic arthritis)
• Malignancy (Neuroblastoma, leukemia, lymphoma, Wilms tumor)
• Emergent conditions that should be ruled out with either H&P or appropriate studies prior to discharging a patient home: 
• Serious Bacterial Infection (source UTI, bacteremia, soft tissue or skin infections)
• Meningitis
• Sepsis
• Septic arthritis: more common in patients under 4 years old
• Epiglottis, bacterial tracheitis, retropharyngeal abscess
• Heat stroke
• Toxic ingestions
• Appendicitis
• Kawasaki disease (prolonged fever, conjunctivitis with perilimbal sparing, red, cracked lips with strawberry tongue, desquamation of skin on hands and feet, cervical lymphadenopathy)
• Orbital cellulitis
• Toxic shock syndrome
  

Summary

Fever in a pediatric patient can be a sign of a self-limited viral illness or a life-threatening bacterial infection. Its causes can be as varied as its presentations. As clinicians, we must use our skills of assessment and data acquisition to determine the risk of SBI.  If that risk is determined to be high the clinician should be prepared to promptly perform the necessary workup and interventions.

References/Further Study

1. Shah VS. Chapter 3. Infectious Diseases. In: Shah BR, Lucchesi M, Amodio J, Silverberg M. eds. Atlas of Pediatric Emergency Medicine, 2e. New York, NY: McGraw-Hill; 2013.
2. ED Pathway for Evaluation/Treatment of Children with Sickle Cell Disease with Fever. The Children’s Hospital of Philadelphia Web site. http://www.chop.edu/clinical-pathway/sickle-cell-disease-fever-clinical-pathway#. Published January 2010. Updated January 2014. Accessed August 2014.
3. Palazzi, DL. Fever of unknown origin in children: Evaluation. In: UpToDate, Torchia, MM (Ed), UpToDate, Waltham, MA (Accessed on August 25, 2014)
4. Orman, R. Pediatric Fever. ERCAST.ORG website. http://blog.ercast.org/pediatric-fever/ Published 27 December 27, 2011. Accessed August 25, 2014.
5. Smitherman, HF, Macias, CG. Evaluation and management of fever in the neonate and young infant (younger than three months of age). In: UpToDate, Wiley, HF (Ed), UpToDate, Waltham, MA (Accessed on August 25, 2014)
6. Kaplan, SL. Bacterial meningitis in children older than one month: Clinical features and diagnosis. In: UpToDate, Torchia, MM (Ed), UpToDate, Waltham, MA (Accessed on August 25, 2014)
7. Wang VJ. “Chapter 113. Fever and Serious Bacterial Illness” in Judith E. Tintinalli, Gabor D. Kelen, J. Stephan Stapczynski, et al. Emergency Medicine: A Comprehensive Study Guide, 7e: 750-55.
8. Fuchs S, Yamamoto L, eds. APLS: The Pediatric Emergency Medicine Resource. 5th Burlington, MA: Jones & Bartlett Learning, 2012.