Internal Medicine Exam Community-Acquired Pneumonia 3

Question 1

A 55-year-old with alcoholism presents with right upper lobe pneumonia and foul-smelling sputum. What organism is the most likely cause?

Accepted Answer

Anaerobes / aspiration flora

Answer

Aspiration pneumonia in alcoholics involves anaerobic organisms from the oropharynx and classically affects dependent lung segments with putrid sputum.

Question 2

Which radiographic pattern is MOST characteristic of Pneumocystis jirovecii pneumonia (PCP) in an immunocompromised host?

Accepted Answer

Bilateral interstitial/perihilar infiltrates

Answer

PCP classically presents with bilateral perihilar interstitial infiltrates on CXR, often with a ground-glass pattern on CT.

Question 3

A 70-year-old develops CAP. Blood cultures are ordered. According to IDSA guidelines, blood cultures are routinely recommended in which scenario?

Accepted Answer

CAP requiring ICU admission

Answer

Current IDSA guidelines recommend blood cultures primarily for severe CAP requiring ICU care, not for all hospitalized patients.

Question 4

Legionella urinary antigen testing detects which serogroup of Legionella pneumophila?

Accepted Answer

Serogroup 1 only

Answer

The Legionella urinary antigen test detects only serogroup 1, which causes approximately 70–80% of Legionella pneumonia cases.

Question 5

Which clinical feature is MOST helpful in distinguishing Legionella pneumonia from pneumococcal pneumonia?

Accepted Answer

Hyponatremia + GI symptoms + elevated LFTs

Answer

Legionella characteristically causes hyponatremia, diarrhea, abdominal pain, and transaminase elevation in addition to pneumonia.

Internal Medicine Exam Practice Test

Internal Medicine Exam Practice Test

Internal Medicine Exam Community-Acquired Pneumonia 3