Pediatrics
A 1-year-old girl presents to the Pediatrics Emergency Department at night with episodes of loud coughing and…
A 1-year-old girl presents to the Pediatrics Emergency Department at night with episodes of loud coughing and refusal to feed. There is a history of upper airway infection with nasal congestion and sneezing over the last week. She has not received any routine immunizations. During the physical examination, there are repetitive violent fits of a hacking cough that are followed by forceful, high-pitched inhalations accompanied by facial cyanosis. Between attacks the girl appears exhausted and apathetic. Heart rate 150 /min Respiratory rate 60 /min Temperature 36.6° C Oxygen saturation 92% on room air Which of the following diagnostic test would be most appropriate?
Explanation
Core Concept:
To diagnose pertussis (*Bordetella pertussis* infection), direct sampling of the respiratory epithelium in the posterior nasopharynx is required because this is where the bacteria preferentially attach and multiply.
Clinical Presentation:
- Symptoms: Unrelenting, paroxysmal coughing spells, often ending in an inspiratory gasp or "whoop," facial flushing/cyanosis, and significant post-tussive exhaustion.
- Complications: Hypoxia, apnea, secondary bacterial pneumonia, and rib fractures from intense coughing.
Diagnosis:
- First-line: Nasopharyngeal swabbing for multiplex PCR, providing rapid turnaround for diagnosis.
- Gold Standard: Nasopharyngeal swab placed on selective media (Bordet-Gengou or Regan-Lowe agar) for bacterial culture.
Management:
- Acute: Initiate targeted antimicrobial therapy with a macrolide (e.g., Azithromycin) to decrease the period of infectivity; provide strict supportive care including oxygen monitoring and nutritional support.
- Definitive/Long-term: Vaccination (DTaP) schedules must be updated and adhered to, along with prophylactic macrolides for vulnerable close contacts.