Basics
Description
- Fever is defined as a temperature of 38 ░C (100.4 ░F) rectally:
- Oral and tympanic temperatures are generally 0.6 ░C-1 ░C lower.
- Tympanic temperatures are not accurate in children younger than 6 mo.
- Axillary temperatures are generally unreliable.
- Children who are afebrile but have a reliable history of documented fever should be considered to be febrile to the degree reported.
Etiology
- Bacteremia (Haemophilus influenzae type B, Streptococcus pneumoniae), viral illness, often accompanied by exanthem (varicella, roseola, rubella), coxsackievirus (hand-foot-and-mouth disease), abscess:
- H. influenzae type B and S. pneumoniae vaccines have reduced incidence of Haemophilus and pneumococcal disease
- CNS: Meningitis, encephalitis
- Head, eyes, ears, neck, and throat (HEENT): Otitis media, facial cellulitis, orbital/periorbital cellulitis, pharyngitis (group A β-hemolytic streptococcus, herpangina, adenovirus pharyngoconjunctival fever), viral gingivostomatitis (herpes and coxsackievirus), cervical adenitis, sinusitis, mastoiditis, conjunctivitis, peritonsillar/retropharyngeal abscess
- Respiratory: Croup (paramyxovirus), epiglottitis, bronchiolitis (respiratory syncytial virus [RSV]), pneumonia, empyema, influenza
- Cardiovascular: Purulent pericarditis, endocarditis, myocarditis
- Genitourinary (GU): Cystitis, pyelonephritis
- GI: Bacterial diarrhea, intussusception, appendicitis, hepatitis
- Extremity: Osteomyelitis, septic arthritis, cellulitis
- Miscellaneous: Herpes simplex virus infection in the neonate, Kawasaki disease, vaccine (DPT) reaction, heat exhaustion/stroke, factitious, familial dysautonomia, thyrotoxicosis, collagen vascular disease, vasculitis, rheumatic fever, malignancy, drug induced, overbundling (uncommon, recheck 15 min after unbundling)
Diagnosis
Signs and Symptoms
- Clinical appearance must be evaluated. Airway, breathing, and circulation (especially dehydration with impaired perfusion/color) need specific evaluation.
- Toxicity associated with lethargy, delayed capillary refill, hypoventilation/hyperventilation, weak cry, decreased PO intake; purpuric or petechial rash, and/or hypotonia. Initial observation is crucial in this evaluation.
- Tachycardia or tachypnea may be the only finding in children with serious underlying condition.
- Fever with a temperature >38 ░C can raise a childs heart rate by 10 bpm for each degree Fahrenheit.
- Temperature >40 ░C have been associated with an elevated bacteremia rate in children <24 mo.
- Altered mental status:
- Lethargy presenting with decreased level of consciousness
- Irritability
- Impaired interaction with environment, parents, physician, toys
- Physical exam (PE) to search for underlying condition
- Tachypnea and low oximetry are the most sensitive signs for pneumonia. Also useful are rales, hypoxemia, cough >10 days, and fever >5 days.
- Risk factors for occult UTI include female sex, uncircumcised boys, fever without source, and fever >39 ░C.
- Febrile seizures
- Temperatures >42 ░C often have a noninfectious cause.
- Serious infection may occur in the absence of fever.
- Antipyretics may change findings without impacting underlying disease. This may be useful in evaluation of patient, esp. with respect to mental status
- ~20% of children will have fever without definable source after history and PE.
Essential Workup
- Oxygen saturation as mandatory 5th vital sign
- Resuscitate as appropriate.
- Determine duration of illness, degree, pattern and height of fever, use of antipyretics, past medical history, drug allergies, immunization status and history, recent medications/antibiotics, birth history if younger than 6 mo of age, exposures, feeding, activity, urine/bowel habits, travel history, and relevant review of systems.
- Search for underlying condition.
- Initiate antipyretic therapy.
Diagnosis Tests & Interpretation
Lab
- CBC with differential
- Urinalysis (UA) and culture in all male infants younger than 6 mo, uncircumcised male infants younger than 12 mo, and females younger than 2 yr. Urines for culture should be obtained by catheterization or suprapubic techniques.
- Blood culture:
- The development of automated blood culture systems has led to more rapid detection of bacterial pathogens.
- CSF for cell counts, Gram stain, culture, protein, and glucose for toxic children and those 0-28/30 days of age; consider for nontoxic-appearing children 28-90 days of age as well as older ones in whom meningitis must be excluded.
- Stool for WBCs and culture when diarrhea present and suggestion of bacterial process
- C-reactive protein (CRP) elevation is commonly found and provides confirmatory data related to the presence of infection. The sedimentation rate (ESR) is also an adjunctive measure.
- Procalcitonin is being used in some settings as additional confirmatory information.
Imaging
- CXR to exclude pneumonia if patient tachypneic or hypoxic
- Other studies as indicated to evaluate for specific underlying infection
Differential Diagnosis
See "Etiology."Ł á
Treatment
Pre-Hospital
- Resuscitate as appropriate.
- Begin cooling with antipyretics.
Initial Stabilization/Therapy
- Treat any life-threatening conditions.
- Antipyretic therapy
- Evaporative cooling techniques, such as sponge bath, have minimal role.
Ed Treatment/Procedures
- Focal infections require evaluation and treatment.
- Toxic children require prompt septic workup and appropriate antibiotics.
- All potential life-threatening conditions must be excluded before treating a minor acute illness, which is more common.
- Infants 0-28 days old need a full sepsis workup: CBC, UA, cultures (blood, urine, CSF), lumbar puncture. A CXR should be obtained if there is suspicion for pneumonia:
- Antibiotics: Ampicillin and either gentamicin or cefotaxime; consider acyclovir for infants at risk for HSV
- Admit
- Well-appearing infants 29-90 days old need workup, selective antibiotic use (ceftriaxone), and re-evaluation within 24 hr:
- H. influenzae type B and S. pneumoniae incidence has declined significantly with widespread vaccination.
- It is currently reasonable to perform CBC, UA, blood culture, and urine culture with selective lumbar puncture, coupled with ceftriaxone IM in low-risk patients (see definition under Disposition) if re-evaluation in 24 hr is ensured. Well-appearing infants 60-90 days of age may be managed without LP or antibiotics selectively.
- While lumbar puncture is optional in this setting, treatment with empiric antibiotics (ceftriaxone) without lumbar puncture may compromise subsequent re-evaluation.
- Presence of RSV or influenza in this age group decreases but does not eliminate the risk of bacteremia and meningitis, but the rate of UTI is still appreciable.
- Children 3 mo-3 yr of age are evaluated selectively; those with recognizable viral syndrome (croup, stomatitis, varicella, bronchiolitis) generally do not require workup unless there is toxicity; antibiotic use is individualized for specific identifiable infections and pending appropriate cultures:
- Well-appearing children with a temperature >39 ░C and no identifiable infection should prompt a UA and culture in all male infants younger than 6 mo, uncircumcised male infants younger than 12 mo, and females younger than 2 yr. Urine for culture should be obtained by catheterization or suprapubic techniques
- Obtaining blood work or performing a lumbar puncture on a child 6 mo-3 yr of age is a clinical decision. Mandatory lumbar puncture in this age group based solely on the presence of fever has not been shown to be cost-effective and is not routinely recommended
- Children 3-6 mo of age who are incompletely immunized and have WBC >15,000/mm3 and no identifiable infection may benefit from empiric antibiotics until preliminary blood cultures are available because of the risk of bacteremia.
- Widespread immunization for Pneumococcus and H. influenzae have decreased the incidence of invasive infections by these bacteria.
- Immunocompromised children need aggressive evaluation, as do children with fever and petechiae/purpura or sickle cell disease.
- If methicillin-resistant S. aureus is considered, clindamycin or trimethoprim-sulfamethoxazole may be useful.
- Patients with underlying malignancy, central venous catheters, or ventricular peritoneal shunts may have few findings other than fever.
Medication
First Line
- Cefotaxime: 100-150 mg/kg/d IV divided q8h
- Ceftriaxone: 50-100 mg/kg/d IV/IM divided q12h
- Vancomycin: 40-60 mg/kg/d IV divided q6-8h if S. pneumoniae suspected until sensitivities defined
- Ampicillin: 150 mg/kg/d IV divided q4-6h
- Gentamicin: 5 mg/kg/d IV divided q8-12h
Second Line
- Acetaminophen: 15 mg/kg per dose PO/PR (per rectum) q4-6h; do not exceed 5 doses/24 h
- Ibuprofen: 10 mg/kg per dose PO q6-8h
- Specific antibiotics for identified or specific conditions
Follow-Up
Disposition
Admission Criteria
- All toxic patients
- Infants 0-28 days of age with temperature >38 ░C
- Nontoxic infants 29-90 days of age with temperature >38 ░C who do not meet low-risk criteria (see definition under Discharge Criteria)
- Patients with fever and petechiae/purpura are generally admitted unless there is a specific nonlife-threatening cause.
- Immunocompromised children
- Poor compliance or follow-up
Discharge Criteria
- Infants 29-90 days of age meeting low-risk criteria:
- No prior hospitalizations, chronic illness, antibiotic therapy, prematurity
- Reliable, mature parents with home phone, available transport, thermometer, and living in relative proximity to ED
- No evidence of focal infection (except otitis media); nontoxic appearing; normal activity, perfusion, and hydration with age-appropriate vital signs
- Normal WBC (5-15,000/mm3), urine (negative Gram stain of unspun urine or leukocyte esterase or <5 WBC/high power field [HPF]), stool (<5 WBC/HPF) if performed, and CSF (<8 WBC/mm3 and negative Gram stain) if performed
- Infants 3-36 mo of age who are nontoxic and previously healthy with good follow-up:
- Follow-up by phone in 12-24 hr and re-evaluate in 24-48 hr with parental instructions to return if concerns develop or patient worsens.
Followup Recommendations
Patients discharged with fever require close follow-up, usually by their primary care provider and guidelines of when to return with any change or worsening of signs or symptoms. á
Pearls and Pitfalls
- Fever is the most common presenting complaint in children. It may reflect a life-threatening condition.
- Children under 28 days of age are generally treated empirically, pending culture results.
- Older children need close follow-up and specific discharge instructions.
- Subtle findings such as tachycardia, tachypnea, or altered mental status may be indicative of significant underlying infection.
Additional Reading
- American Academy of Pediatrics. Red Book 2012: Report of the Committee on Infectious Diseases. 29th ed. Elk Grove, IL: AAP; 2012.
- Baraff áLJ. Management of fever without source in infants and children. Ann Emerg Med. 2000;36:602-614.
- Gomez áB, Bressan áS, Mintegi áS, et al. Diagnostic value of procalcitonin in well-appearing young febrile infants. Pediatrics. 2012;130:815-822.
- Huppler áAR, Eickhoff áJC, Wald áER: Performance of low-risk criteria in the evaluation of young infants with fever: A review of the literature. Pediatrics. 2010;125:228-233.
- Krief áWI, Levine áDA, Platt áSL, et al. Influenza virus infection and the risk of serious bacterial infections in young febrile infants. Pediatrics. 2009;124:30-39.
- Ralston áS, Hill áV, Waters áA. Occultserious bacterial infection in infants younger than 60 to 90 days with bronchiolitis: A systemic review. ArchPediatr Adolesc Med. 2011;165:951-956.
- Subcommittee on Urinary Tract Infection, Steering Committee on Quality Improvement and Management, Roberts áKB. Urinary tract infection: Clinical practice guideline for the diagnosis and management of the initial UTI in febrile infants and children 2 to 24 months. Pediatrics. 2011;128(3):595-610.
Codes
ICD9
- 780.60 Fever, unspecified
- 780.61 Fever presenting with conditions classified elsewhere
ICD10
- R50.9 Fever, unspecified
- R50.81 Fever presenting with conditions classified elsewhere
SNOMED
- 386661006 fever (finding)
- 7520000 Pyrexia of unknown origin (finding)
- 95627000 fever of the newborn (disorder)