Actinomycosis (pulmonary)

Pulmonary actinomycosis accounts for 15-20% of cases.

• may result from
  • aspiration of oropharyngeal secretions
  • oesophageal perforation
  • local spread from cervicofacial or abdominal infection
  • haematogenous spread.
• a higher incidence of pulmonary actinomycosis is seen in patients with underlying lung disease such as emphysema, chronic bronchitis, and bronchiectasis
• it may coexist with lung disease such as tuberculosis or malignancy making the diagnosis and treatment challenging
  • initial clinical picture may be similar to pneumonia with a low-grade fever, cough, shortness of breath, and chest pain
  • however, there is usually a longer history of illness and associated weight loss and haemoptysis.
• complications may include:
  • empyema necessitans (a rare complication of empyema in which the pleural infection spreads to affect the soft tissues of the chest wall)
  • pleural effusion
  • mediastinal invasion
    • can progress into the heart causing pericarditis (commonly)
  • rib destruction
  • less often myocarditis or endocarditis may occur either via extension from the pericardium or by haematogenous spread (1)

Reference:

• (1) Wong VK, Turmezei TD, Weston VC. Actinomycosis. BMJ. 2011;343:d6099