Clinical Pearl: The classic triad of pertussis—paroxysmal coughing, inspiratory whoop, and post-tussive vomiting—may not be present in infants younger than 6 months. In this age group, apnea and cyanosis are often the primary presenting signs, making a high index of suspicion critical.
Stages of Pertussis
- Catarrhal Phase (1-2 weeks): Highly contagious stage with nonspecific symptoms (rhinorrhea, low-grade fever, mild cough). Often indistinguishable from a common cold.
- Paroxysmal Phase (1-6 weeks): Characterized by the hallmark fits of rapid, uncontrollable coughing. The inspiratory whoop occurs as the patient gasps for air. Infants may exhibit gagging, gasping, or a frightened look instead of a classic whoop.
- Convalescent Phase (weeks to months): Gradual resolution of coughing paroxysms, though intermittent episodes can recur with subsequent respiratory infections.
Key Nursing Assessment
- Observe the Cough: Watch for a complete coughing episode. Note the pattern: a series of rapid coughs on one breath followed by a sudden, forceful inspiration.
- Monitor for Complications: Assess for apnea, cyanosis, and signs of increased intracranial pressure (bulging fontanelles) from severe coughing. Pneumonia is a common secondary complication.
- Feeding and Hydration: Evaluate for post-tussive vomiting and poor feeding, which can lead to dehydration and failure to thrive.
Infection Control & Management
- Isolation: Implement droplet precautions immediately. The patient is highly contagious during the catarrhal and early paroxysmal phases.
- Diagnosis: Nasopharyngeal swab for PCR or culture is the gold standard. Leukocytosis with lymphocytosis is a classic but nonspecific lab finding.
- Treatment: Macrolide antibiotics (e.g., azithromycin) are the first-line treatment to reduce infectivity. Administer early in the catarrhal phase for best effect; during the paroxysmal phase, treatment limits spread but may not alter symptom duration. Supportive care includes oxygen, gentle suctioning, and small, frequent feedings.