Select onset (acute, subacute), stridor (inspiratory, biphasic), wheeze (expiratory), fever, drooling, cough quality, and position (sniffing, tripod) → differentiate croup, epiglottitis, bacterial tracheitis, foreign body, asthma, bronchiolitis, and retropharyngeal abscess.
⚠️ Red flags: stridor, drooling, toxic appearance → epiglottitis (do not examine pharynx, immediate airway). Biphasic stridor → subglottic or tracheal lesion.
Select stridor (inspiratory, biphasic, expiratory), wheeze, retractions, grunting, cough quality (barking, staccato), fever, drooling, positioning, and age → differentiate croup (viral laryngotracheobronchitis), epiglottitis (Hib, stridor, drooling, toxic), bacterial tracheitis, foreign body, asthma, bronchiolitis (RSV), and retropharyngeal abscess.