Acute otitis externa

Question 1

What are the risk factors for acute OE?

Answer 1

1. swimming
2. trauma
3. foreign body in the ear
4. using a hearing aid
5. certain dermatological conditions
6. chronic otorrhea
7. wearing tight head scarves
8. immunocompromised
9. ear piercing –> infection of the pinna

Question 2

How do you diagnose acute otitis externa?

Answer 2

1. rapid onset (generally within 48h) in the past 3 weeks
   AND
2. symptoms of ear canal inflammation including:
   - otalgia, itching, or fullness
   - WITH or WITHOUT hearing loss or jaw pain
   AND
3. signs of ear canal inflammation, including:
   - tenderness of the tragus, pinna or both
   OR
   - diffuse ear canal edema, erythema, or both
   - WITH or WITHOUT otorrhea, regional lymphadenitis, tympanic membrane erythema or cellulitis of the pinna and adjacent skin

Question 3

What organisms cause AOE?

Answer 3

1. Pseudomonas aeruginosa
2. Staphylococcus aureus
3. Polymicrobial
4. Gram negative bacteria
5. Rare fungal infections w/ Aspergillus or Candida species

Question 4

What is the treatment for mild-to-moderate AOM?

Answer 4

1. Topical antibiotics w/ or w/out topical steroids x 7-10d
2. Adequate pain control w/ acetaminophen, NSAID, or opioid
3. Aural toileting and wick therapy to facilitate topical medication delivery and decrease canal edema

Question 5

What is the treatment for severe AOE?

Answer 5

Systemic antibiotics that cover S. aureus and P. aeruginosa

Question 6

When should clinical response occur?

Answer 6

Within 48-72h but full response can take up to 6d

Question 7

What should non-response prompt evaluation for?

Answer 7

1. obstruction
2. presence of foreign body
3. non-adherence to therapy
4. alternative diagnosis i.e. viral, fungal, dermatitis

Question 8

What is malignant OE?

Answer 8

Invasive infection of the cartilage and bone of the canal and external ear which may present w/ facial nerve palsy and pain

Question 9

Who is at risk of malignant OE?

Answer 9

Immunodeficient patients

Patients w/ insulin-dependent diabetes

Question 10

What is the management of malignant OE?

Answer 10

1. CT or MRI to confirm
2. Aggressive debridement
3. Systemic antibiotics targeted at P. aeruginosa and possibly Aspergillus

Question 11

How do you prevent AOE?

Answer 11

1. Insert soft malleable plug to prevent water in canal
2. remove water from the ears after swimming via positioning and shaking head
3. daily prophylaxis w/ alcohol or acidic drops during at risk activities not studied
4. avoid hard earplugs

Question 12

What medications are available in Canada for AOE?

Answer 12

Polysporin, neosporin, cortisporin, sofracort, ciprodex, Buro-sol, garasone, garamycin