A patient with Type 1 diabetes mellitus was treated for otitis externa with topical drops and now has persistent foul discharge and granulations. What is the proper treatment at this time?

• A. Ciprofloxacin (Cipro) IV
• B. Cefuroxime (Zinacef) IV
• C. Ampicillin-sulbactam (Unasyn) PO
• D. Azithromycin (Zithromax) PO

Answer: (A)

When a diabetic patient with otitis externa has persistent foul discharge and granulation tissue, think about malignant otitis externa, an infection that can extend beyond the external canal to involve the skull base and surrounding structures. This requires systemic therapy with an antipseudomonal antibiotic given IV, because topical drops alone won’t reach the deeper tissues and bone.

IV ciprofloxacin is the best choice here because it provides strong activity against Pseudomonas aeruginosa and penetrates bone and infected tissues well, which is essential for this serious infection. The other options don’t offer reliable antipseudomonal coverage or the necessary IV access: cefuroxime has limited activity against Pseudomonas, azithromycin isn’t effective against Pseudomonas, and while ampicillin-sulbactam can cover some gram-negatives, it’s not the preferred choice for malignant otitis externa and oral administration isn’t appropriate for this severe presentation.