Hot Seat #147: A Febrile Infant

Posted on: March 8, 2020, by :

Case: 10 wk old ex-36wk boy (though otherwise healthy: no major prior surgeries and no other medical problems) presents to the ED with fever. He received his 2 month vaccines 4 days prior and has been having daily fevers since this time (Tm-102). He was seen in the ED 2 days ago where he had a partial workup done which included CBC (WBC- 18K with neutrophil predominance), UA/UCx (negative), and Blood  Cx (NGTD). He received ceftriaxone and was discharged. Since this time he has continued to have daily fevers, but is otherwise acting like himself. He was sent in today by urgent care for “an elevated white count” in the setting of continued fevers.  Parents deny any URI symptoms, no coughing or breathing difficulty, no vomiting or diarrhea. He is fussy with fever, but is otherwise acting like himself. No known sick contacts. He is drinking the same amount and making 6-8 wet diapers per day. ROS otherwise normal.

Exam:

Vitals: T- 38.6; HR- 186; RR-44; BP: 97/73; SaO2- 100% on RA

Gen: alert, awake, social smile

HEENT: AFOSF, Scant nasal congestion, TMs clear, non-erythematous,

Neck: No lymphadenopathy or meningismus 

Pulm: CTAB

CV: tachycardic, but no murmurs. Cap refill is 1-2 seconds and he has 2+ radial and DP pulses

Ab: soft, NTND, +BS

GU: circumcised, no rashes

Skin: no rashes

Neuro: non-focal

You decide to repeat blood culture, CBC, and obtain an RVP.

CBC shows WBC is now 23K with 71% neutrophils, 24% lymphocytes, and 1% immatures; Hb- 7.7 (8.1 two  days prior), PLT- 673 (635 two days prior). RVP is negative, 2ndblood culture pending.

The child continues to look well and parents want to know what the plan is. At this point, he has drank 3 bottles, and made 3 wet diapers. His HR has normalized and he is currently afebrile; exam is otherwise unchanged. Attempts to reach PCP are unsuccessful, but parents are confident they can get an appointment in the morning if needed.

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1 thought on “Hot Seat #147: A Febrile Infant


  1. There are a lot of things we could discuss about this patient, but I’ll pick one topic specifically: his late preterm birth. Several studies after the Hib vaccines have placed the incidence of serious bacterial infection (SBI) in infants between 1 and 3 months of age at around 10%. Our patient has a postconceptual age of 46 weeks, so is he more likely to have an SBI? A study from Loma Linda, Kaiser, and Desert Regional Medical Center (“Incidence of Serious Bacterial Infections in Ex-premature Infants with a Postconceptional Age Less Than 48 Weeks Presenting to a Pediatric Emergency Department” by N Inoue et al.) found that the incidence of SBI in ex-premature infants like our patient here to be 9.2% – similar to published rates in term infants. All that is to say is that I would treat this patient like the 10-week old that he is.

    And, given that he is well-appearing, doesn’t have respiratory symptoms, is tolerating PO, and seems to have reliable follow-up – I wouldn’t act on an elevated WBC alone and just have him follow up with his PMD without empiric antibiotics. The one thing that would give me pause is if the PMD disagreed with this management plan – a case that quickly comes to mind is a patient with cellulitis in whom the parents felt comfortable with discharge on PO antibiotics but the PMD said that “if the parents bring the child to my office tomorrow, I’m just going to send them back to the ED.” We ended up admitting the patient because why put the family through an additional office and ED visit for the same outcome?

    My two (overly extensive) cents!

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