mrcem2-0349

You are requested to evaluate a 75-year-old male who has been referred to the emergency department after visiting his local Boots™ store for a hearing assessment. The patient reports experiencing pain and hearing impairment on the right side a few days prior to the examination. The nurse who examined the patient’s ears before conducting the audiogram expressed concerns regarding malignant otitis externa.

What is the primary cause of malignant otitis externa?