A 27-year-old man comes to the Emergency Department for review. He has recently returned
from a diving training trip to the Caribbean and complains of severe cellulitis and irritation
affecting his right ear. He has been diving both in the sea and in a large heated training pool.
He has no past medical history of note and takes no regular medication.
Examination reveals an erythematous right external auditory meatus with obvious
discharging pus, which has a very strong odour. The right eardrum appears not to have
perforated. There is no significant pain on palpation of the skull around the ear.
Which is the most appropriate intervention?