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 child's 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 028/30 days of age; consider for nontoxic-appearing children 2890 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."
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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 028 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 2990 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 6090 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 mo3 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 mo3 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 36 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 trimethoprimsulfamethoxazole 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: 100150 mg/kg/d IV divided q8h
- Ceftriaxone: 50100 mg/kg/d IV/IM divided q12h
- Vancomycin: 4060 mg/kg/d IV divided q68h if S. pneumoniae suspected until sensitivities defined
- Ampicillin: 150 mg/kg/d IV divided q46h
- Gentamicin: 5 mg/kg/d IV divided q812h
Second Line
- Acetaminophen: 15 mg/kg per dose PO/PR (per rectum) q46h; do not exceed 5 doses/24 h
- Ibuprofen: 10 mg/kg per dose PO q68h
- Specific antibiotics for identified or specific conditions
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DISPOSITION 
Admission Criteria
- All toxic patients
- Infants 028 days of age with temperature > 38°C
- Nontoxic infants 2990 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 2990 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 (515,000/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 336 mo of age who are nontoxic and previously healthy with good follow-up:
- Follow-up by phone in 1224 hr and re-evaluate in 2448 hr with parental instructions to return if concerns develop or patient worsens.
FOLLOW-UP 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.
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