Pulmonary lesion

The pathogenesis of the pulmonary lesions are described:

• it is suggested that bacteria adhere more easily to the abnormal epithelium and that mucus cannot be efficiently cleared
• chronic bacterial infection results in mucus gland hypertrophy, mucus hypersecretion and further infection
• the bronchial wall is damaged and bronchiectasis develops
• when established bronchiectasis is present and mucociliary transport is compromised, then clearance of the lungs is increasingly dependent on gravity and cough
• principal pathogens include:
  • Haemophilus influenzae
  • Staphylococcus aureus
  • later, Pseudomonas aeruginosa and other pseudomonads
• small areas of parenchymal consolidation and fibrosis may develop as a result of impaired clearance
• in advanced disease there is increasing destruction of lung tissue and emphysema