Chapter 69 Otitis Externa

Question 1

What is the definition of otitis externa?

Answer 1

Cellulitis of the external auditory canal that may extend to the auricle

Often referred to as swimmer’s ear, with varied causes.

Question 2

What percentage of people develop otitis externa over their lifetime?

Answer 2

Approximately 10%

About 95% of these cases are acute otitis externa.

Question 3

What are the risk factors for developing otitis externa?

Answer 3

• Removal of protective cerumen
• Damage to fragile skin from vigorous cleaning
• Maceration of skin from moisture accumulation
• Use of headphones and ear plugs

These factors compromise the integrity of the defense mechanism against infection.

Question 4

What are the most common causative organisms of otitis externa in the United States?

Answer 4

• Pseudomonas aeruginosa
• Staphylococcus aureus

Fungi like Candida and Aspergillus are uncommon causes.

Question 5

What is the usual presentation of acute otitis externa?

Answer 5

• Pain of the affected ear
• Feeling of fullness or itching
• Drainage from the ear
• Hearing loss

Pain develops over 48 hours or less.

Question 6

What is the classic finding in acute otitis externa?

Answer 6

Pain and tenderness on palpating the tragus and repositioning the auricle

The canal may be erythematous and edematous.

Question 7

What are the essential diagnostics for otitis externa?

Answer 7

• Culture of canal drainage
• Potassium hydroxide preparation of drainage

Culture is indicated if there is no improvement after 14 days of antibiotic therapy.

Question 8

What are the priority differentials for otitis externa?

Answer 8

• Acute otitis media
• Malignant otitis externa
• Chronic suppurative otitis media

Important to distinguish from other conditions causing ear pain.

Question 9

What is the pharmacologic management for mild to moderate pain in otitis externa?

Answer 9

• Nonsteroidal anti-inflammatory drugs (NSAIDs)
• Acetaminophen

NSAIDs provide analgesia and control inflammation.

Question 10

What should be done for severe pain in otitis externa during the initial 48 to 72 hours?

Answer 10

Opioids may need to be given

Opioids should not be prescribed routinely.

Question 11

What is the management focus for otitis externa?

Answer 11

• Clearing debris from the canal
• Managing pain
• Treating infection and inflammation

Accomplished through both pharmacologic and nonpharmacologic therapy.

Question 12

What is the most common complication of malignant otitis externa?

Answer 12

Invasive osteomyelitis of the ear

Occurs when bacterial infection extends into cartilage and bone.

Question 13

What is the age group most commonly affected by otitis externa?

Answer 13

Young people

Malignant otitis externa primarily affects older patients.

Question 14

What is the treatment for fungal infections causing chronic otitis externa?

Answer 14

• Acidification with 5% acetic acid
• Antifungal solutions like clotrimazole otic
• Fluconazole if no contraindications

Acidification may cause a stinging sensation.

Question 15

What should patients with otitis externa be educated about?

Answer 15

• Causes
• Management
• Prevention

Important to review medication administration and potential adverse effects.

Question 16

What is a recommended method to dry the ear after swimming to prevent otitis externa?

Answer 16

Use a blow dryer

A mixture of white vinegar and rubbing alcohol drops can also help.