Pediatrics 409384.A 9-day-old boy is brought to the ED for fever and fussiness. He was
born full-term. However, the delivery was complicated by prolonged rup-
ture of membranes (PROM) and the mother had a fever for which she was
treated with antibiotics prior to delivery. The baby did well in the nursery
and has been at home and feeding without any difficulties until the day of
presentation when he became more fussy, less interested in feeding, and the
parents noted a temperature of 101.5°F (measured under patient’s arm).
On presentation, his temperature is 102.4°F, HR 160 beats per minute, RR
48 breaths per minute, and pulse oxymetry of 97% on room air. His ante-
rior fontanelle is open and flat, conjunctivae are clear, neck is supple with-
out masses, and the heart, lungs, and abdominal examinations are normal.
The skin shows tiny (1–3 mm) pustules with a surrounding rim of ery-
thema on the patient’s trunk. No vesicular lesions are noted. The most
likely organism responsible for this patient’s condition is:
a. Escherichia coli
b. Listeria monocytogenes
c. Group B streptococcus
d. Staphylococcus aureus
e. Herpes simplex virus
385.An 11-year-old girl presents to the ED with a 3-day history of
decreased energy and difficulty climbing stairs. The patient had previously
complained of pain in her lower extremities last week and was seen by her
primary-care physician when she was diagnosed with muscle cramping.
She has no complaints of focal tenderness or history of trauma. On exami-
nation, the patient is afebrile with normal vital signs. Her neurologic exami-
nation is significant for marked lower extremity weakness and absent deep
tendon reflexes. Her sensory examination is normal. The upper extremities
reveal normal strength and sensation throughout. Which of the following
would be most helpful to confirm the suspected diagnosis?
a. Emergency magnetic resonance imaging (MRI) of the spine
b. Deep muscle biopsy
c. Electrolytes looking for decreased potassium
d. Lumbar puncture
e. Edrophonium challenge