Severe Cough with Vomiting and Dyspnea Without Postnasal Drip
This clinical presentation strongly suggests pertussis (whooping cough), and you should immediately start empiric macrolide antibiotic therapy without waiting for diagnostic confirmation. 1
Immediate Diagnostic Assessment
Assess for the key clinical features of pertussis:
- Paroxysmal cough (recurrent prolonged coughing episodes with multiple bursts of outflow and inability to breathe during spells) 1
- Post-tussive vomiting (vomiting induced by coughing) - this is a highly suggestive feature in adults 1
- Inspiratory whooping (continuous inspiratory airway sound with whooping quality) 1
- Absence of fever - while fever rules out pertussis in adults, its presence does NOT exclude pertussis in children 1, 2
When cough has been present for ≥2 weeks and is accompanied by paroxysmal coughing with post-tussive vomiting and/or inspiratory whooping, diagnose pertussis unless another diagnosis is proven. 1
Diagnostic Testing
Order nasopharyngeal aspirate or Dacron swab for culture immediately - this is the only certain way to confirm the diagnosis, though you should not delay treatment while awaiting results. 1, 2
- Culture isolation of Bordetella pertussis provides definitive confirmation 2
- PCR testing is available but lacks universally standardized validation for routine clinical use 1, 2
- Paired acute and convalescent sera showing fourfold increase in IgG or IgA antibodies to pertussis toxin or filamentous hemagglutinin can provide presumptive diagnosis 1
Immediate Treatment
Start azithromycin (preferred macrolide) immediately without waiting for culture results. 2
- Alternative macrolides include erythromycin, clarithromycin, or roxithromycin 1
- Early treatment within the first few weeks diminishes coughing paroxysms and prevents disease spread 2
- Isolate the patient for 5 days from the start of antibiotic treatment to prevent transmission 2
Supportive Management
- Provide frequent small feedings to prevent aspiration, as post-tussive vomiting leads to weight loss and feeding difficulties 2
- Maintain a calm, quiet environment to minimize coughing triggers 2
- Monitor for complications including pneumothorax, subconjunctival hemorrhage, and secondary bacterial pneumonia 2
Alternative Diagnoses to Consider
If pertussis is ruled out and cough persists 3-8 weeks (subacute postinfectious cough):
- Trial inhaled ipratropium as first-line therapy to attenuate cough 1
- If ipratropium fails and cough adversely affects quality of life, consider inhaled corticosteroids 1
- For severe paroxysms after ruling out upper airway cough syndrome, asthma, and GERD, consider prednisone 30-40 mg daily for a short finite period 1
- Central acting antitussives (codeine or dextromethorphan) should be considered when other measures fail 1, 3
If cough-variant asthma is suspected (though less likely without wheeze):
- Cough-variant asthma presents solely with cough and shares pathophysiological features with classic asthma including airway hyperresponsiveness and eosinophilic inflammation 4
- Bronchoprovocation testing can help when baseline pulmonary function tests are normal 5
- Inhaled corticosteroids are the most important treatment and reduce risk of progression to classic asthma 4
Critical Pitfalls to Avoid
- Do not delay pertussis treatment waiting for culture confirmation if clinical suspicion is high based on paroxysmal cough with post-tussive vomiting 1, 2
- Do not assume antibiotics have no role - while most acute bronchitis is viral and doesn't require antibiotics, pertussis is a critical bacterial exception requiring immediate macrolide therapy 1, 6
- Do not dismiss the diagnosis based on absence of whooping - post-tussive vomiting alone in adults with acute or subacute cough is sufficient to consider pertussis likely 1