| Suspected diagnosis | Signs and symptoms | Diagnostic evaluation |
| Acute |
| Asthma | - History of recurrent wheeze, cough
- At least partial response to bronchodilator
| - History
- PFT with bronchodilators
- Empiric trial of bronchodilators
- Exercise or methacholine challenge testing
- Chest radiography only if atypical
- Skin (or in vitro) testing for aeroallergen sensitization if history suggests inhalant allergen triggers
|
| Viral bronchiolitis | - Prodrome with rhinitis
- Occurs in infancy and early childhood
- Seasonal pattern
| - History, age, season
- In selected cases, rapid antigen testing (RSV, influenza), viral cultures, chest radiography
|
| Foreign body | - Sudden onset of coughing and wheezing
| - History
- Physical examination
- Chest radiography
- Rigid bronchoscopy
|
| Chronic |
| Asthma | | |
| Tracheomalacia | - Persistent wheeze, starts early in life
- Poor response to bronchodilators
- Varies with position and activity
| - History
- Fluoroscopy
- Flexible bronchoscopy or dynamic CT with airway protocol
|
| Cystic fibrosis | - Chronic productive cough
- Crackles, with or without clubbing
- FTT
- Recurrent respiratory infections
| - Sweat chloride test
- Genetic testing
|
| Swallowing dysfunction | - Neurologic abnormality (nonuniversal)
- Choking with eating
- Symptoms exaggerated by feeding
| - Videofluoroscopic swallowing study (modified barium swallow)
|
| Gastroesophageal reflux | - Symptoms sometimes related to eating, vomiting, refusal to eat
- FTT
| - 24-hour esophageal pH monitoring
- Multichannel intraluminal impedance monitoring
|
| Vascular ring or sling | - Persistent symptoms, starts early in infancy
- May be exaggerated by position
- Homophonous wheeze
| - Chest radiograph, MRI, or CT angiogram
- Barium swallow
|
| Tracheal stenosis | - Persistent symptoms, with or without stridor
- Homophonous wheeze
| - Chest radiograph
- CT scan
- Bronchoscopy
|
| Mediastinal nodes or mass | - Persistent symptoms
- Localized wheezing
- No response to bronchodilator
- Systemic symptoms of underlying disease
| |
| Immunodeficiency | - Recurrent sinopulmonary infections
- Crackles
- FTT
- Clubbing
| - Immunoglobulins
- Vaccine responses
|
| Primary ciliary dyskinesia | - Persistent sinusitis and otitis media with draining ears
- Recurrent respiratory infection
- Wet cough with sputum production
- Crackles
- Clubbing
- FTT
| - Ciliary biopsy
- Genetic testing
- Exhaled nasal nitric oxide (ENO)
|
| Inducible laryngeal obstruction (vocal cord dysfunction) | - Inspiratory stridor
- Poor response to bronchodilators
- Absent symptoms during sleep
- Most commonly occurs in adolescents
- Exercise related
| - Exercise testing
- PFT
- Laryngoscopy while symptomatic
|
| Bronchiolitis obliterans | - History of predisposing disease (ie, viral infection or transplantation)
- Dyspnea
- Persistent wheezing
| - Chest CT scan
- In rare cases, lung biopsy is needed
|
