The management of a febrile infant is complex and requires obtaining a detailed history of all possible exposures. Published guidelines alone are not always completely accurate for diagnosing or excluding serious illness, and are not a substitute for a thorough examination and history.
Case
The parents of a 45-day-old girl were referred to our regional pediatric hospital by a local community hospital for emergent evaluation of their infant. The day prior, they had taken the infant to the referring ED because of persistent fussiness and subjective fever. They were neither sure of the tests that were obtained during that visit nor why they were instructed to take their daughter to our pediatric facility. They did, however, recall that during the visit to the community ED, the patient had a rectal temperature of 102.7°F, was given an antibiotic injection, and was well appearing and acting normally. Also, at discharge, the infant’s parents were instructed to follow up with the patient’s pediatrician within 24 hours.
Since their daughter’s discharge from the community ED, both parents noted that she seemed more irritable, felt warm, and had not been feeding well. They confirmed that she was an otherwise healthy infant who had been born full term via normal vaginal delivery and without complications.
On initial assessment at our ED, the patient was fussy and had mottled extremities and dusky nail beds. Her vital signs at presentation were: heart rate, 223 beats/minute; respiratory rate, 36 breaths/minute; and rectal temperature, 103.6°F. Oxygen saturation was 96% on room air. The infant was resuscitated with 20 mL/kg of intravenous (IV) normal saline and given oral acetaminophen. Laboratory studies were obtained, and a lumbar puncture (LP) was performed.
She was treated with IV acyclovir, ceftriaxone, and vancomycin. Her complete blood count (CBC) was notable for a white blood cell count (WBC) of 22.60 x 109/L; cerebrospinal fluid (CSF) analysis revealed a WBC of 4.52 x 109/L with 75% neutrophils, and serum glucose of 63 mg/dL.
Since the patient’s parents did not have any paperwork or information from the prior ED visit, our ED contacted the community ED by phone, and a representative provided the following information: the patient had appeared well but was febrile at presentation; laboratory evaluation was obtained, but no LP was performed; she was treated with intramuscular (IM) ceftriaxone and acetaminophen; and she was discharged home in the care of her parents. Regarding laboratory studies performed at the community ED, the only test result made available by phone was the preliminary blood culture report that revealed growth of gram-negative rods with speciation pending, which prompted the referral to our facility.
Based on the information provided by the community ED and our evaluation and work-up, the patient was admitted to the pediatric intensive care unit. Magnetic resonance imaging (MRI) of the brain was performed, which showed debris in the lateral ventricles consistent with ventriculitis—likely secondary to meningitis. The blood, urine, and cerebrospinal fluid (CSF) cultures collected during our evaluation produced no growth; however, blood cultures from the rural ED eventually grew Salmonella.
A further detailed history revealed that the infant and her parents had been living with a family friend who owned an iguana. According to reports, the iguana had free run of the home and often crawled around and across the infant while she was lying on a blanket on the floor. The patient’s parents were not aware of the diseases associated with reptile contact. Due to concerns over the social situation, the patient was kept in the hospital for the entire recommended 21-day course of antibiotic therapy, during which time the parents received assistance finding alternate living arrangements.
Discussion
Current Practice Guidelines for Managing Febrile Infants
Current guidelines from the American Academy of Pediatrics (AAP) and the American College of Emergency Physicians (ACEP) recommend a full sepsis work-up for all neonates (ie, ages 0 to 28 days) who present with a fever (defined as a rectal temperature ≥100.4°F).1,2 The probability of a serious bacterial infection (SBI) in patients in this age group who present with fever is approximately 12%.3 A full sepsis work-up generally includes a CBC, blood cultures, urinalysis with culture, CSF analysis with culture, and stool cultures if diarrhea is present.
Current guidelines for infants 29 to 90 days of age who present with fever differ between professional associations. The AAP and the American Academy of Family Physicians recommend the following for children in this age range: laboratory evaluation with CBC, blood cultures, CSF analysis, urinalysis, and culture. If laboratory evaluation reveals a WBC of less than 15 x 109/L with an absolute neutrophil count of less than 10 x 109/L, along with a normal CSF and urinalysis, the patient can be given IM ceftriaxone and follow-up arranged in 24 hours. This approach is recommended for patients who are otherwise healthy, nontoxic at presentation, and under the care of a responsible adult.4,5 By comparison, the Philadelphia protocol, though suggesting an identical work-up, recommends against the use of antibiotics in infants deemed at low risk for SBI.6