A wheezy infant unresponsive to bronchodilators.

When infants with recurrent wheezing have a clinical course inconsistent with asthma, an extensive list of alternative diagnoses needs to be considered. Anatomic malformations, such as congenital heart disease, laryngotracheomalacia, and diaphragmatic hernia, should be considered for immediate medical stabilization and early surgical correction. Life-threatening infections such as bacterial epiglottitis, retropharyngeal cellulitis, and viral myocarditis require prompt intervention. A careful history and physical examination reveal important diagnostic clues that, in this case, prompted a directed evaluation to rule out common masqueraders of asthma such as foreign body aspiration, cystic fibrosis, gastroesophageal reflux, viral pneumonitis, or pulmonary tuberculosis. On occasion, such a search is unrevealing and a diagnostic challenge remains. In those situations, judicious use of modern technology to scrutinize anatomic (high-resolution computed tomography) and functional (infant pulmonary function tests) pathology, and justifiable invasive procedures such as bronchoscopy and lung biopsy, uncover the true diagnosis, allowing for optimal management.