Otitis Externa

Question 1

Otitis Externa Aetiology

Answer 1

• Disturbance of the lipid/acid balance of the ear canal
• Most usually infectious can be caused by allergies or irritants
• Necrotising usually caused by P. aeruginosa

Question 2

Otitis Externa Infections

Answer 2

• 90% bacterial and 10% fungal
• Most involve multiple organisms
• Staph aureus, P, aeruginosa
• Fungal infection usually follows prolonged treatment with antibiotics
• Ramsay Hunt
• Derm causes
• Irritant causes e.g. earplugs

Question 3

Otitis Externa Presentation

Answer 3

• Pain and itching are main symptoms
• Discharge and hearing loss
• Systemic symptoms if severe
• Can be malignant and extend into temporal bones
• Facial nerve palsy is red flag
• Perforation if can taste medication put in ear or can blow air out of ear

Question 4

Otitis Externa Investigations

Answer 4

• Swabs if treatment failure
• Cultures not that reliable, easily contaminated
• Topical antibiotics much higher concentration, most organisms susceptible

Question 5

Otitis Externa Differentials

Answer 5

• Foreign bodies
• Impacted wax
• Otitis media

Question 6

Otitis Externa Management

Answer 6

• Topical drops
• Acetic acid for mild cases
• Topical antibiotics for most cases (neomycin or clioquinol)
• Oral if cellulitis, cervical lymphadenopathy or systemic illnes
• Same day assessment if systemic symptoms
• Do not use aminoglycosides (ototoxicity)
• Can insert ear-wick (usually done by specialist)
• Aural toilet