Pediatric Staphylococcus Pneumonia

  • Etiology:
    — Staphylococus aureus bacteria
    — Less than 1 year old has endobronchial spread, older children have hematogeneous spread
  • Imaging CXR AP: Look for silhouette sign to locate pulmonary opacity to correct lobe: lingular bacterial pneumonia usually obscures left heart border, right middle lobe bacterial pneumonia usually obscures right heart border, lower lobe bacterial pneumonia usually obscures hemidiaphragm
  • Imaging CXR Lateral: Look for spine sign of lower lobe bacterial pneumonia: normally lung should get more lucent going from lung apex to lung base, if lung gets more dense going from lung apex to lung base you have lower lobe bacterial pneumonia
  • Imaging US: Heterogenous hypoechoic echotexture similar to liver = hepatization of lung
  • DDX: White-out of lung
    — Wth complete atelectasis of lung heart and mediastinum are shifted ipsilaterally
    — With pneumonia and large pleural effusion heart and mediastinum are shifted contralaterally
  • Complications: Can cause effusion or empyema in 90%, pneumatocele in 50%, pneumothorax in 10%
  • Treatment: Antibiotics
  • Clinical: Bacterial pneumonia in lower lobes can present with abdominal pain due to irritation of the diaphragm and mimic acute appendicitis so look at lungs on AXR and CT

Radiology Cases of Staphylococcus Pneumonia

Radiology Cases of Staphylococcus Pneumonia with Pneumatocele

CXR of pneumatocele
CXR shows a large thin walled cystic lesion in the left lower lobe.

Radiology Cases of Staphylococcus Pneumonia with Lung Abscess

CXR of lung abscess in cystic fibrosis
CXR shows a round cavitary lesion with an air-fluid level in the left upper lobe.

Radiology Cases of Staphylococcus Pneumonia with Pleural Empyema

CXR and CT of pediatric pleural empyema
CXR (above left) shows near complete opacification of the right hemithorax with no evidence of mediastinal shift. Coronal (above right) and axial (below) CT with contrast of the chest shows a large right pleural fluid collection that has multiple loculations within it which is causing complete collapse of the right lung.