Discussion: Foreign-body ingestion or aspiration is most common in children <3 yo. The most commonly aspirated objects are food items, and most common ingestion is coins. A high index of suspicion, witnessed event, and history of choking are most important for diagnosis.
Upper airway foreign body (FB) symptoms include hoarseness, aphonia, stridor, inspiratory wheeze, acute respiratory distress. Lower airway symptoms include expiratory wheeze, shortness of breath, asymmetric aeration of lung fields, unexplained coughing spells, respiratory distress, fever. Alternately, patients may be asymptomatic for weeks-months before presentation, or may have only subtle or nonspecific symptoms. Diagnosis can be delayed if symptoms are misinterpreted as pneumonia, asthma, or bronchiolitis.
Ingested FB presents with droolng, throat pain, dysphagia, odynophagia, localizable neck pain, or respiratory distress d/t compression of the airway from esophageal FB.
Diagnostic workup for foreign body aspiration begins with plain film of the chest. Radiopaque objects are readily seen; however, the majority of aspirated FBs are organic and radiolucent, therefore diagnosis is suggested by secondary changes. The most common site of FB is the bronchus, and CXR changes include hyperinflation, mediastinal shift, post-obstructive lobar or segmental infiltrates, or pneumothorax.
Conversely, the radiograph can appear completely normal in up to 2/3 of patients. When airway foreign body is suspected and the inspiratory chest radiograph is normal, expiratory films can be done in cooperative patients, and bilateral decubitus or airway fluoroscopy in uncooperative patients. These may show hyperinflation/air trapping distal to the foreign body in the dependent lung. Again, negative studies do not rule out foreign body.
Chest xrays are usually normal in laryngotracheal FBs. PA and lateral neck xrays can suggest laryngotracheal FB if they show subglottic density or swelling.
Other studies such as CT may be used if erosion or extraluminal extension is suspected, or less commonly in nonemergent cases where diagnosis is questionable. CT can help in diagnosing and determining exact location of the foreign body in patients with false-negative expiratory and decubitus radiographs. However, CT exposes the child to radiation, requires patient cooperation/sedation, does not often contribute to the diagnosis and may delay the treatment.
More commonly, bronchoscopy is the next diagnostic step after radiography.
With a history of choking and suggestive symptoms and PE findings, foreign body aspiration should be presumed despite a negative chest radiograph. Bronchoscopy is the standard of care in most centers for the evaluation and management of children with suspected FB aspiration.
