5. Clinical: EAC

Question 1

What is otitis externa?

Answer 1

Inflammation of the external auditory canal

Question 2

What is the most common organism causing otitis externa?

Answer 2

Pseudomonas aeruginosa

Question 3

What is malignant otitis externa?

Answer 3

Severe infection of the EAC that spreads to the skull base, especially in diabetics or immunocompromised patients

Question 4

What is the treatment for malignant otitis externa?

Answer 4

Intravenous ciprofloxacin or ceftazidime for 6–8 weeks

Question 5

What is keratosis obturans?

Answer 5

Accumulation of keratin debris causing EAC widening, pain, and hearing loss

Question 6

What is the narrowest part of the external auditory canal?

Answer 6

Isthmus

Question 7

What does a positive tragal sign indicate?

Answer 7

Pain on tragus pressure suggests otitis externa

Question 8

What is the hallmark appearance of Aspergillus niger in otomycosis?

Answer 8

Black spores with a ‘wet newspaper’ appearance

Question 9

What is the significance of the foramen of Huschke?

Answer 9

A developmental defect that may allow spread of infection to adjacent structures

Question 10

Which cranial nerves may be involved in skull base osteomyelitis due to malignant otitis externa?

Answer 10

CN VII (Facial), IX (Glossopharyngeal), X (Vagus), XI (Accessory)