11/7/2013

11/7/2013

Answers:

The facial nerve is --- to the EAC.
A) Posterior 
B) Anterior 
C) Medial 
D) Lateral 
E) Inferior 
F) Superior

The mastoid segment of the facial nerve runs posterior to the EAC.

Is cerumen acidic or alkalotic?

Cerumen is acidic. This helps prevent bacterial infection. In fact, the presence of water causes alkylosis of the EAC which then allows increased growth of bacteria/fungi which can lead to otitis externa.

MC Questions:
All of the following contribute to sensory innervation of the external ear except...
A) CNV 
B) CNVII 
C) CNVIII 
D) CNX 
E) Great Auricular nerve

Free Response Question:
Name the vascular supply to the external ear.

Quick Facts:

Otitis Externa:
-Pseudomonas/Staph are most common organisms.
-Predisposing factors include heat, humidity, maceration, absence of cerumen and alkaline pH.
-In inflammatory phase, bacterial overgrowth occurs and edema/pain ensues.
-If persistent for >3months = chronic
-Symptoms include: otalgia, otorrhea, aural fullness, pruritus, tenderness to palpation, occlusion of EAC (CHL).
-Signs include pain of pinna, EAC erythema, otorrhea, crusting, LAD of periauricular and ant. cervical lymph nodes
-Treat w/ meticulous atraumatic debridement of EAC.
-Use otic drop, antiseptic/acidifying/antibiotic. All equally effective.
-Use wick if canal severe.
-Use systemic abx if extends beyond EAC.
-If chronic consider canalplasty
-Pt should avoid EAC movement and water exposure.