Acute | Asthma | Bronchiolitis* | Laryngotracheobronchitis¶ | Atypical infection (Mycoplasma pneumonia)Δ | Bacterial tracheitis | Foreign body aspiration¶ | Esophageal foreign body | | Chronic or recurrent | Structural abnormalities | Tracheo-bronchomalacia* | Vascular compression/rings* | Tracheal stenosis/webs* | Cystic lesions/masses | Tumors/lymphadenopathy | Cardiomegaly | Functional abnormalities | Asthma | Gastroesophageal reflux | Recurrent aspiration | Cystic fibrosis | Immunodeficiency | Primary ciliary dyskinesia | Bronchopulmonary dysplasia | Retained foreign body (trachea or esophagus) | Bronchiolitis obliterans | Pulmonary edema | Inducible laryngeal obstruction (vocal cord dysfunction)Δ | Interstitial lung disease | |