A 70-year-old patient with long-standing type 2 diabetes mellitus presents with complaints of pain in the left, ear with purulent drainage. On physical examination, the patient is afebrile. The pinna of the left ear is tender, and the external auditory canal is swollen and edematous. The white blood cell count is normal. Which of the following organisms is most likely to grow from the purulent drainage?
Ear pain and drainage in an elderly diabetic patient must raise concern about malignant external otitis. The swelling and inflammation of the external auditory meatus strongly suggest this diagnosis. This infection usually occurs in older, poorly controlled diabetics and is almost always caused by P aeruginosa. It can invade contiguous structures including facial nerve or temporal bone and can even progress to meningitis. Streptococcus pneumoniae, H influenzae, and M catarrhalis frequently cause otitis media, but not external otitis. Candida albicans almost never affects the external ear.
Pseudomonas aeruginosa
Streptococcus pneumoniae
Candida albicans
Haemophilus influenzae
Infection