Pneumonia

Question 1

Lobar

Answer 1

S. pneumoniae most frequently, Klebsiella

Intra-alveolar exudate –> consolidation; may involve entire lung

Question 2

Bronchopneumonia

Answer 2

S. pneumoniae, S. aureus, H influenzae, Klebsiella

Acute inflammatory infiltrates from bronchioles into adjacent alveoli; patchy distribution involving > 1 lobe

Question 3

Interstitial (atypical) pneumonia

Answer 3

Viruses (influenza, RSV, adenoviruses), Mycoplasma, Legionella, Chlamydia

Diffuse patchy inflammation localized to interstitial areas at alveolar walls; distribution involving > 1 lobe. Generally follows a more indolent course