Diagnosis: Postinfectious Cough with Transient Bronchial Hyperresponsiveness
The diagnosis in an adult with no prior asthma presenting with post-infectious cough and wheeze is postinfectious cough with transient bronchial hyperresponsiveness, a self-limited condition lasting 3-8 weeks following a respiratory infection. 1
Clinical Framework
This presentation represents a subacute cough (lasting >3 weeks but <8 weeks) following an upper respiratory tract infection. The wheeze indicates transient airway hyperresponsiveness—a key complication of postviral airway inflammation—but this is not asthma in a patient without prior history 1.
Key Pathophysiologic Features
The ACCP guidelines identify multiple pathogenetic factors contributing to postinfectious cough 1:
- Postviral airway inflammation with extensive epithelial disruption
- Transient bronchial hyperresponsiveness (causing the wheeze)
- Mucus hypersecretion and impaired mucociliary clearance
- Importantly: eosinophilic inflammation typical of asthma is absent 1
Diagnostic Criteria
Consider postinfectious cough when:
- Cough present for ≥3 weeks but ≤8 weeks following acute respiratory infection 1
- Normal chest radiograph (ruling out pneumonia) 1
- No prior asthma history
If cough persists >8 weeks, consider alternative diagnoses including upper airway cough syndrome (UACS), gastroesophageal reflux disease, or true asthma 1
Critical Differential: Pertussis
Suspect Bordetella pertussis infection if the cough includes: 1
- Paroxysms of coughing
- Posttussive vomiting
- Inspiratory whooping sound
- Duration >2 weeks without another apparent cause
This requires nasopharyngeal culture for definitive diagnosis and macrolide antibiotic treatment if confirmed 1.
Important Clinical Pitfalls
Do not misdiagnose this as new-onset asthma. While wheeze is present, the guidelines emphasize that bronchial hyperresponsiveness in postinfectious cough occurs without the eosinophilic inflammation characteristic of asthma 1. The hyperresponsiveness is transient and self-limited.
The chest radiograph must be normal—this distinguishes postinfectious cough from pneumonia or other structural lung disease 1.
Etiologic Agents
Common causative organisms include 1:
- Respiratory viruses (RSV, influenza, parainfluenza, adenovirus)
- Mycoplasma pneumoniae
- Chlamydophila pneumoniae
- Moraxella catarrhalis
- Bordetella pertussis
Most cases remain unidentified, and the diagnosis is clinical and one of exclusion 1.
Prognosis
This condition is self-limited and will resolve spontaneously, typically within 8 weeks 1. The transient nature of the bronchial hyperresponsiveness distinguishes it from true asthma, which would persist beyond this timeframe.