(b) Source: (Hay et al, pp 499-500. Kliegman et al, pp 1453-1454. McMillan et al, pp 693-694. Rudolph et al, pp 449-451.) Recurrent pneumonias in an otherwise healthy child should suggest the potential for anatomic blockage of an airway. In the patient in this question, the findings on clinical examination suggest a foreign body in the airway. Inspiratory and expiratory films can be helpful. Routine inspiratory films are likely to appear normal or near normal (as outlined in the question and noted in the first radiograph). Expiratory films will identify air trapping behind the foreign body (as noted on the second radiograph). It is uncommon for the foreign body to be visible on the plain radiograph; a high index of suspicion is necessary to make the diagnosis. Suspected foreign bodies in the airway are potentially diagnosed with fluoroscopy, but rigid bronchoscopy is not only diagnostic but also the treatment of choice for removal of the foreign body.