Table 2 Suggested indications for performing a chest radiograph in a child with acute cough
IndicationFeaturesLikely common diagnoses
Uncertainty about the diagnosis of pneumoniaFever and rapid breathing in the absence of wheeze/stridorLocalising signs in chest*Persisting high fever or unusual course in bronchiolitisCough and fever persisting beyond 4–5 daysPneumoniaN.B. Chest radiograph is not always indicated: use to resolve uncertainty or in more severe cases†
Possibility of an inhaled foreign bodyChoking episode may not have been witnessed but cough of sudden onset or presence of asymmetrical wheeze or hyperinflationInhaled foreign bodyExpiratory film may help in acute bronchial obstruction, but normal chest radiograph does not exclude foreign body.Bronchoscopy is the most important investigation.
Pointers suggesting that this is a presentation of a chronic respiratory disorderFailure to thriveFinger clubbingOverinflated chestChest deformitySee section on chronic cough
Unusual clinical courseCough is relentlessly progressive beyond 2–3 weeksRecurrent fever after initial resolutionPneumoniaEnlarging intrathoracic lesionTuberculosisInhaled foreign bodyLobar collapse
Is there true haemoptysis?‡Acute pneumoniaChronic lung disorder (eg, cystic fibrosis)Inhaled foreign bodyTuberculosisPulmonary haemosiderosisTumourArteriovenous malformation
  • *Dull percussion, reduced air entry, crackles or bronchial breathing.

  • †Community-acquired pneumonia guidelines.3840

  • ‡True haemoptysis needs to be differentiated from spitting out blood secondary to nose bleeds, cheek biting, pharyngeal and oesophageal or gastric bleeding.