Indication | Features | Likely common diagnoses | ||
Uncertainty about the diagnosis of pneumonia | Fever 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 days | PneumoniaN.B. Chest radiograph is not always indicated: use to resolve uncertainty or in more severe cases† | ||
Possibility of an inhaled foreign body | Choking episode may not have been witnessed but cough of sudden onset or presence of asymmetrical wheeze or hyperinflation | Inhaled 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 disorder | Failure to thriveFinger clubbingOverinflated chestChest deformity | See section on chronic cough | ||
Unusual clinical course | Cough is relentlessly progressive beyond 2–3 weeksRecurrent fever after initial resolution | PneumoniaEnlarging 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.38–40
‡True haemoptysis needs to be differentiated from spitting out blood secondary to nose bleeds, cheek biting, pharyngeal and oesophageal or gastric bleeding.