A nurse is providing discharge instructions to the parent of a 3-year-old toddler who is in the emergency department for croup, Which of the following conditions should the nurse instruct the parent to monitor for to prevent spasmodic croup?

A. Spasmodic croup is often triggered by allergic reactions or exposure to irritants, such as pollen, dust, or environmental allergens. Unlike viral croup, spasmodic croup is non-infectious and usually occurs at night, presenting with sudden onset of barking cough and stridor. Parents should monitor for and minimize allergen exposure to prevent recurrence. B. While viral infections (e.g., parainfluenza virus) cause classic croup, they are not the primary trigger for spasmodic croup, which is typically allergic or irritant-related rather than infectious. C. Inhalation of warm, humid air is often therapeutic, not causative, for spasmodic croup. Warm mist can soothe inflamed airways and reduce stridor, making it a recommended home intervention rather than a risk factor. D. Bacterial infections are rare causes of croup and are associated with bacterial tracheitis, which is more severe and distinct from spasmodic croup. Bacterial infection is not a typical trigger for spasmodic croup.