Otitis Externa

Question 1

What is otitis externa?

Answer 1

(swimmers’ ear)

Inflammation and infection of the ear canal

Question 2

What causes otitis externa?

Answer 2

Excess canal moisture e.g. due to swimming or high humidity
Minor trauma from cleaning and using hearing aids
Diabetes
Chronic skin conditions – eczema and psoriasis

Bacteria pseudomonas aeruginosa, staph aureus.
Fungal – aspergillus and candida
Contact dermatitis

Question 3

What are the clinical features of otitis externa?

Answer 3

Discharge (otorrhoea)
Itch 
Pain 
Tragal tenderness
Usually no high fever unless extreme 
Red and swollen canal on otoscopy 
Swollen auricular lymph nodes

Can last from 6 weeks to 3 months

Question 4

How do you classify otitis externa?

Answer 4

Mild – scaly red skin, normal diameter of EAC,

Moderate – painful, narrowed EAC, discharge,

Severe – EAC occluded,

Question 5

What investigations should be done in a suspected otitis externa?

Answer 5

Examination
Inflammatory markers
Swab and culture

Question 6

What is the management of otitis externa?

Answer 6

Avoid sticking anything in the ear
Avoid swimming or washing hair
Clean canal – gentle syringing or irrigation, dry mopping under direct vision, microsuction

Topical antibiotic such as ciprofloxacin, gentamicin or ofloxacin (avoid aminoglycosides if perforated) plus topical steroid. Topical acetic acid also effective.
If struggling to access the skin of the canal insert a thin ear wick with aluminium acetate to assist opening of canal

Second line
Oral antibiotics – flucloxacillin or clarithromycin (if penicillin allergic)
Antifungals – clotrimazole, acetic acid or clioquinol and a corticosteroid

Question 7

What must you be aware of in otitis externa in diabetic or immunocompromised patients?

Answer 7

Note persistent OE in diabetic/immunosuppressed patients may indicate necrotising OE
OE resistant to treatment may suggest SCC – do biopsy

Question 8

What is necrotising otitis externa?

Answer 8

Life threatening condition in immunocompromised patients that can result in temporal bone erosion and skull base osteomyelitis. 90% of those affected are diabetic. Most commonly caused by pseudomonas aeruginosa which gives a distinctive smell.

Question 9

What are the clinical features of malignant/necrotising otitis externa?

Answer 9

Cardinal signs are excruciating pain and problems sleeping
Cranial nerve palsies (facial and vagus)
No relapse even when swelling goes down
Temporal headaches and purulent otorrhea

Question 10

What investigations should be ordered in suspected malignant otitis externa?

Answer 10

Swabs

CT

Question 11

What is the management for malignant otitis externa?

Answer 11

Referral to ENT
Surgical debridement
Systemic (IV) antibiotics (ciprofloxacin or gentamicin)
Specific Immunoglobulins

Question 12

What is furunculosis?

Answer 12

Painful staphylococcal abscess arising in a hair follicle. Should be lanced and drained. Common in diabetics. If pinna cellulitis, then start flucloxacillin.