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Difficulty: MediumNeonatal Disorders

A 24-hour-old male newborn is evaluated in the nursery for respiratory distress. He was born at 39 weeks of gestation via spontaneous vaginal delivery to a 24-year-old primigravida. The mother had ruptured membranes 22 hours prior to delivery. Her group B *Streptococcus* (GBS) status is unknown due to a lack of prenatal care. The infant weighed 3.2 kg (7 lb 1 oz) at birth. Apgar scores were 8 and 9 at 1 and 5 minutes, respectively. Current vital signs include a temperature of 38.4°C (101.1°F), heart rate of 175/min, and respiratory rate of 72/min. Physical examination reveals nasal flaring, mild subcostal retractions, and expiratory grunting. The skin examination demonstrates multiple scattered erythematous macules containing central 1- to 2-mm yellow-white pustules over the infant's chest, abdomen, and back. The palms and soles are spared. Microscopic evaluation of a Wright-stained smear from one of the pustules reveals numerous eosinophils. Which of the following is the most appropriate next step in the management of this patient?

  1. A
    Apply topical mupirocin to the skin lesions and initiate oral cephalexin
  2. B
    Obtain a blood culture and initiate intravenous vancomycin and ceftriaxone
  3. C
    Obtain viral swabs of the skin lesions and initiate intravenous acyclovir
  4. Obtain a blood culture and initiate intravenous ampicillin and gentamicinAnswer
  5. E
    Administer nebulized albuterol and initiate intravenous corticosteroids

Answer

Obtain a blood culture and initiate intravenous ampicillin and gentamicin
The correct answer is to obtain a blood culture and initiate intravenous ampicillin and gentamicin. This infant presents with fever, tachycardia, and respiratory distress in the setting of prolonged rupture of membranes (greater than 18 hours) and unknown maternal GBS status, which is highly suspicious for early-onset neonatal sepsis (EOS). The most common pathogens responsible for EOS are Group B Streptococcus (GBS) and Escherichia coli, followed by Listeria monocytogenes. The gold standard empiric antibiotic regimen for EOS is intravenous ampicillin (which covers GBS and L. monocytogenes) and an aminoglycoside such as gentamicin (which covers E. coli and other Gram-negative enteric bacteria). The infant's rash is erythema toxicum neonatorum, a benign condition characterized by eosinophils on a Wright-stained smear, which spontaneously resolves and does not require specific treatment.

Step-by-Step Solution

1
Analyze the newborn's vital signs and clinical presentation.
The infant is febrile (38.4°C) with tachycardia, tachypnea, and signs of respiratory distress (retractions, grunting).
To recognize systemic instability indicative of early-onset neonatal sepsis (EOS).
2
Evaluate the maternal history for neonatal risk factors.
The mother had prolonged rupture of membranes (> 18 hours) and unknown GBS status, which are major risk factors for EOS.
Risk factors guide the suspicion and empiric management of neonatal infections.
3
Interpret the skin findings and Wright stain results.
Erythematous macules with central pustules showing eosinophils are diagnostic of erythema toxicum neonatorum (ETN), a benign condition.
To distinguish benign neonatal rashes from infectious etiologies (e.g., HSV, staphylococcal pustulosis) that would require targeted treatment.
4
Determine the appropriate management.
The patient requires a workup for early-onset sepsis and empiric treatment with intravenous ampicillin and gentamicin.
Ampicillin covers GBS and Listeria monocytogenes, while gentamicin covers Gram-negative organisms like E. coli. Ceftriaxone must be avoided in neonates.

Key Concept

Empiric treatment of suspected early-onset neonatal sepsis involves a full diagnostic workup and initiation of ampicillin and gentamicin; concurrent benign findings like erythema toxicum neonatorum must be recognized to prevent inappropriate targeted therapies.
Estimated Time:1m 30s
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Topics

Neonatal Disorders

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