Repeated USMLE Questions Step 1- 161

A 68 year-old man with a long history of poorly controlled diabetes presents to his physician complaining of pain and drainage in his left ear. His vital signs are within normal limits. The pinna of his left ear is tender. The external meatus is swollen and covered with purulent drainage.

What is the most likely organism responsible for his condition?

A-Candida albicans

B-Homophilus influenzae

C-Pseudomonas aeruginosa

D-Moraxella catarrhalis

E-Streptococcus pneumoniae






Answer:

This infection is most likely malignant otitis externa and caused by pseudomonas aeruginosa. It is common in elderly people and specifically those with a history of poorly controlled diabetes. Other organisms mainly cause otitis media but they very rarely affect external ear.

The correct answer is C