14-month-old unvaccinated child presenting with 1 day of bulging fontanelle. Two days prior to presentation patient had 3 episodes of non-bloody non-bilious emesis. In between these episodes she did tolerate PO without emesis and was acting at her baseline so family monitored her at home. Yesterday,  she was still having normal PO intake, was no longer vomiting, but developed fever to 102 F. Family gave antipyretic and she seemed more comfortable after defervesce. Today on day of presentation, patient has new nasal congestion and decreased intake with only 2-3 wet diapers. She is much more irritable and has a decrease in energy level.  Mom also notes that the baby’s eyes looks a little swollen and her anterior fontanelle is bulging significantly. This fontanelle bulging was new as of today and was not present on the prior two days. Family denies any recent head injuries. Family went to urgent care earlier today where she was noted to be febrile, had a bulging fontanelle, and was sent to the ED for further management.  Patient has been waiting in the ED waiting room for over 6 hours at time of evaluation.

Vital Signs: Temp 40.4 HR 199 RR 36 BP 127/71 SpO2 98%
General:  awake, alert, vigorous infant who is quite irritable with any exam maneuvers, feels warm to touch, able to be calmed by mom when not being touched/examined, notable bulging fontanelle which is apparent on visual inspection 
Skin:  Warm.  dry.  no rashes no purpuric or petichiael lesions.  
Head:  Normocephalic.  bulging tense anterior fontanelle visible on visual inspection and on palpation is tense and clearly elevated above skull.  
Neck:  no apparent meningismus but does cry with most exam maneuvers and repositioning 
Eye:  Pupils are equal, round and reactive to light.  extraocular movements are intact.  normal conjunctiva. 
Ears, nose, mouth and throat:  Oral mucosa moist.  No intraoral lesions.  
Cardiovascular:  tachycardic, no apparent murmur, strong radial and DP pulses, strong femoral pulses, cap refill <2 seconds in fingers and toes
Respiratory:  non-tachypneic, no increased work of breathing, no retractions or accessory muscle use, normal aeration bilaterally without wheeze, crackles or other adventitious sounds
Gastrointestinal:  Soft.  Nontender.  Non distended.  
Genitourinary:  Normal external genitalia for age
Musculoskeletal:  Moves all extremities
Neurological:  moves all extremities; normal extraocular movements; irritable with exam but consolable, observed comfortably sleeping on a second reassessment

You decide to obtain CBC, CMP, CRP, Procalcitonin, Aerobic Blood Culture, cath UA and urine culture, and start empiric ceftriaxone and vancomycin based on the patient’s unvaccinated status, high fever, and bulging fontanelle.

The CBC showed WBC 6.2, Hb 10.6, ANC 3490 with 18% bands, ALC 2680, procal 0.95 (elevated), CMP unremarkable.

You inform family that you plan to obtain a lumbar puncture but you decide to obtain head imaging first and order a CT Head.

CT Head is performed and revealed: Slightly prominent extra-axial space with CSF fluid density underlying the anterior fontanelle. Mild bulging of anterior fontanelle. No skull fracture. No acute intracranial changes.

While you were waiting for the results to come back and obtaining LP consent from the family, mom shares the following additional history: she had similar bulging fontanelle when she had a fever about 5 weeks prior to today’s presentation; family did a telemedicine visit with a provider at their PCP office, mom pointed out the bulging fontanelle but at that time the was not irritable and was acting at her baseline so only supportive care was recommended. Mom states that the bulging  subsided shortly after that visit and then just reappeared today.  You also find out that the child is not completely unvaccinated and did receive 2 month and 4-month-old vaccines, but none since.

As you’re waiting for a team member to help you hold for the LP, the RVPCR results positive for influenza B. The patient has defervesced after receiving tylenol, repeat vitals show temp 37.2, HR 138, RR 28, BP 119/76, SpO2 100%.