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Difficulty: MediumPediatric Neurologic Disorders

A 4-week-old girl is brought to the pediatric emergency department for a 3-day history of a progressively weak cry, poor feeding, and decreased spontaneous movement. Her parents report she has not had a bowel movement in 5 days. They mention she has been fussy recently, and they began dipping her pacifier in local honey to soothe her. She has also had a mild cough and rhinorrhea over the past week. On physical examination, her temperature is 37.2°C (99.0°F), pulse is 150/min, and respiratory rate is 42/min. The infant exhibits generalized hypotonia, a prominent head lag, and symmetric ptosis. Gag and deep tendon reflexes are absent. Lung auscultation reveals mild, scattered end-expiratory wheezes. Skin examination shows scattered erythematous macules and papules on her cheeks, which the parents note appeared a week ago. Which of the following is the most appropriate next step in management?

  1. A
    Administration of intravenous ceftriaxone and ampicillin
  2. B
    Administration of nebulized albuterol and oral corticosteroids
  3. Administration of human-derived botulism immune globulinAnswer
  4. D
    Administration of intravenous acyclovir
  5. E
    Reassurance and routine outpatient follow-up

Answer

The correct answer is the administration of human-derived botulism immune globulin, which neutralizes the circulating botulinum toxin.
The correct answer is the administration of human-derived botulism immune globulin. This infant's presentation of constipation, weak cry, ptosis, absent gag reflex, and descending flaccid paralysis is classic for infant botulism. The ingestion of raw honey is a well-known risk factor, as it contains Clostridium botulinum spores. In the immature infant gut (which lacks protective normal flora), these spores germinate and produce botulinum toxin. The toxin irreversibly binds to presynaptic membranes at the neuromuscular junction and cleaves SNARE proteins, preventing acetylcholine release. Because the toxin's binding is irreversible, recovery requires the regeneration of new nerve terminals. Human-derived botulism immune globulin neutralizes only the freely circulating toxin. Therefore, it must be administered as soon as the clinical diagnosis is suspected, without waiting for confirmatory stool studies, to halt the progression of the paralysis and minimize the length of intensive care stay.

Step-by-Step Solution

1
Analyze the infant's neurologic symptoms and dietary history.
The combination of constipation, weak cry, ptosis, and descending flaccid paralysis (hypotonia, absent reflexes) in an infant fed honey is highly suspicious for infant botulism.
Clostridium botulinum spores in honey germinate in the infant's immature gastrointestinal tract, producing a neurotoxin that blocks presynaptic acetylcholine release.
2
Determine the immediate next step in management for suspected infant botulism.
Human-derived botulism immune globulin (BabyBIG) should be administered immediately.
Treatment must not be delayed for confirmatory stool testing. Early administration neutralizes circulating toxin, halting the progression of paralysis and reducing the need for prolonged mechanical ventilation.
3
Evaluate the incidental clinical findings to rule out alternative diagnoses.
The wheezing represents a concurrent viral upper respiratory infection (bronchiolitis), and the facial rash is benign neonatal cephalic pustulosis.
Identifying these as incidental findings prevents inappropriate interventions (such as broad-spectrum antibiotics, antivirals, or asthma medications) and maintains focus on the primary, life-threatening neuromuscular blockade.

Key Concept

Infant botulism typically presents with constipation followed by bulbar weakness and descending flaccid paralysis, often linked to honey ingestion; it requires immediate treatment with human-derived botulism immune globulin without waiting for laboratory confirmation.
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Topics

Pediatric Neurologic Disorders

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