Risk factors associated with community-acquired lung abscess:
(1) aspiration
(1a) loss of consciousness
(1b) intoxication (alcoholism, other)
(1c) seizure disorder
(1d) drugs or medical conditions associated with loss of pharyngeal control
(2) impaired host defenses
(2a) diabetes mellitus
(2b) therapy with corticosteroids
(3) pre-existing lung cavity (malignancy, cavitary tuberculosis, etc)
(4) smoking
Some patients will have no identifiable risk factor (idiopathic).
Certain bacteria are more likely to cause a lung abscess rather than other forms of lung infection:
(1) anaerobic bacteria
(2) Klebsiella pneumoniae
(3) microaerophilic Streptococci
(4) Nocardia asteroides
