Parenchymal necrosis with confined cavitation that results from a pulmonary infection

Aetiology

• Usually a preceding illness e.g. pneumonia
• Can be due to a septic embolism e.g. PWID

Risk factors

• Immunodeficiency
• Immunosuppression
• Abnormal innate immunological defence
• Repeated insult
• History of stroke or other conditions which can increase risk of aspiration of oropharyngeal secretions

Clinical features

• Typically presents as a pneumonia that worsens despite treatment
• Weight loss
• Cough +/- sputum
• Lethargy, tiredness, weakness
• Finger clubbing can be seen in patients with recurrent lung abscesses

Investigations

• CXR: walled cavity
• CT: can be used to differentiate between an empyema and an abscess

Management