Examkin

Question

Difficulty: MediumPediatric Neurologic Disorders

A 4-month-old boy is brought to the emergency department by his parents due to a 3-day history of progressively worsening difficulty feeding and a 'weak' cry. The parents note that he has not had a bowel movement in 5 days. He was born at 39 weeks gestation without complications. He is exclusively breastfed but was recently given a pacifier dipped in honey to soothe him. Vital signs are within normal limits. Physical examination reveals a lethargic infant with bilateral ptosis, sluggish pupillary light reflexes, and pooling of oral secretions. When pulled by the arms to a sitting position, he exhibits pronounced head lag. Deep tendon reflexes are trace diffusely. Which of the following is the most appropriate next step in management?

  1. Administration of human-derived botulism immune globulinAnswer
  2. B
    Administration of equine-derived botulinum antitoxin
  3. C
    Stool assay for Clostridium botulinum spores before initiating therapy
  4. D
    Empirical intravenous ampicillin and gentamicin
  5. E
    Reassurance and outpatient physical therapy evaluation

Answer

The most appropriate next step in management is the immediate administration of human-derived botulism immune globulin.
This patient's presentation of constipation followed by acute-onset bulbar dysfunction (ptosis, weak cry, pooling secretions) and descending flaccid paralysis (head lag, hypotonia) is highly characteristic of infant botulism. The condition is caused by the ingestion of Clostridium botulinum spores, commonly found in raw honey or environmental dust. These spores germinate in the infant's gastrointestinal tract and produce a neurotoxin that irreversibly inhibits the presynaptic release of acetylcholine at the neuromuscular junction. When infant botulism is strongly suspected clinically, the most appropriate next step is the immediate administration of human-derived botulism immune globulin (BIG-IV). Treatment must be given empirically and without delay, as early administration significantly reduces the length of hospital stay and the need for mechanical ventilation.

Step-by-Step Solution

1
Analyze the clinical presentation.
The patient is a 4-month-old with acute-onset constipation, bulbar weakness (ptosis, sluggish pupils, weak cry, pooling secretions), and descending flaccid paralysis (pronounced head lag, trace reflexes).
Identifying the classic triad of constipation, bulbar palsies, and descending paralysis points directly to infant botulism.
2
Identify the risk factor and pathogenesis.
The infant was given honey, which contains Clostridium botulinum spores that germinate in the immature infant gut and produce neurotoxin.
Confirming the exposure solidifies the clinical diagnosis of infant botulism as opposed to foodborne botulism (preformed toxin).
3
Determine the optimal management step.
Select empirical treatment with human-derived botulism immune globulin (BIG-IV).
BIG-IV specifically neutralizes the unbound toxin in infants, avoids the anaphylaxis risks of equine antitoxin, and must be given immediately without waiting for diagnostic confirmation.

Key Concept

Infant botulism presents with constipation followed by bulbar and descending flaccid paralysis; it requires immediate empirical treatment with human-derived botulism immune globulin (BIG-IV).
Rate this question

Topics

Pediatric Neurologic Disorders

More questions from this topic