Etiology, Clinical Presentation, and Complications of Lung Abscess

Etiology of Lung Abscess

A lung abscess is a localized area of lung tissue necrosis caused by microbial infection. Common etiological factors include:

• Aspiration of oropharyngeal secretions (common in patients with impaired consciousness or dysphagia)
• Necrotizing pneumonia caused by bacterial pathogens such as Staphylococcus aureus, Klebsiella pneumoniae, or Pseudomonas aeruginosa
• Bronchial obstruction due to malignancy or foreign body
• Hematogenous spread from distant infections

Risk Factors

Certain conditions predispose individuals to lung abscess formation, including:

• Alcoholism and altered mental status (due to aspiration risk)
• Periodontal disease and poor dental hygiene
• Immunosuppression (e.g., HIV/AIDS, chemotherapy)
• Tracheostomy and prolonged mechanical ventilation

Pathophysiology

Once bacteria invade lung tissue, an inflammatory response leads to localized necrosis and cavity formation. The resulting abscess may contain pus and may rupture into the bronchi, leading to expectoration of foul-smelling sputum.

Clinical Presentation

Patients with lung abscess may present with:

• Persistent fever and malaise
• Cough with copious purulent or foul-smelling sputum
• Pleuritic chest pain
• Weight loss and night sweats

Complications

Complications of lung abscess include:

• Bronchopleural fistula leading to empyema
• Sepsis and systemic dissemination
• Chronic pulmonary infection

Conclusion

Lung abscess remains a serious pulmonary condition, requiring timely diagnosis and appropriate antimicrobial therapy to prevent complications.