Otitis externa

Question 1

What is otitis externa?

Answer 1

An infection of the external auditory canal

Question 2

What are the two most common causes of otitis externa?

Answer 2

Pseudomonas aeruginosa
Staphylococcus aureus

Question 3

What are the symptoms of otitis externa?

Answer 3

Ear pain
Discharge
Itchiness
Conductive hearing loss

Question 4

What are the signs of otitis externa on examination?

Answer 4

Erythema and swelling of the ear canal
Tenderness of the ear canal
Pus/discharge in the ear canal
Lymphadenopathy
Fever

Question 5

What are the risk factors for otitis externa?

Answer 5

Diabetes
Deramtitis
Trauma
Moisture - swimming, humid environment

Question 6

What investigations are used in the diagnosis of otitis externa?

Answer 6

Swab - for microbiological analysis
Otoscopy
Blood glucose - poor blood glucose control in a diabetic can exacerbate infection

Question 7

What is the management of mild otitis externa?

Answer 7

Topical 2% acetic acid

Question 8

What is the management of moderate otitis externa?

Answer 8

Topical antibiotic and steroid
- Neomicin, dexamethasone and acetic acid
- Ciprofloxacin 3% with dexamethasone
- Clotrimazole 1% if fungal infection suspected

Question 9

What is malignant otitis externa?

Answer 9

Infection spread to the bones surrounding the ear canal and skull
- Progresses to osteomyelitis of the temporal bone

Question 10

What is the management of malignant otitis externa?

Answer 10

Admission under ENT team
IV antibiotics
CT or MRI head to assess extent of infection