iPTX3 exam 5: Otitis Externa

what is the pathophysiology of otitis externa?

skin desquamation that leads to microscopic fissues

obstruction, absence of cerumen, trauma, and pH changes can cause it too

what structures of the ear can be affected in otitis externa?

Pinna, tympanic membrane

what are the S/sx associated with otitis externa?

ear pain, itching, sense of fullness, +/- hearing loss or jaw pain, pinna or tragus tenderness, pinna cellulitis, discharge

how fast can the S/sx of otitis externa present itself?

48 hours

what microbes are the main culprits of otitis externa?

Pseudomonas, S. aureus

What are the rare fungal microbes that can cause otitis externa?

Aspergillus, Candida

T or F:

Swab cultures should be taken for otitis externa

False

What are the risk factors for developing otitis externa?

Swimming/prolonged water exposure, soap irritation, Type A blood

what anatomical abnormalities can cause otitis externa?

Canal stenosis, Exostoses, hairy ear canals

what dermatologic conditions can cause an increase likelihood of developing otitis externa?

Eczema, psoriasis, seborrhea

what non-pharmacologic treatment can be used for otitis externa?

Aural toilet

what is the preferred medication for pain management of otitis externa?

PO analgesic

T or F:

A topical steroid has been shown to quicken pain relief

True

What is the first-line treatment for otitis externa?

Topical ABx w/o topical steroid

T or F:

Topical application for otitis externa is often 100 - 1000x higher in concentration than systemic

True

What patients are excluded from ABx treatment for their otitis externa?

Immunodeficient, T2DM, extension of the infection outside of the ear canal

what are the main ABx used for otitis externa?

Ciprofloxacin, Ofloxacin

T or F:

Quinolone ABx carry an increased risk for tympanic membrane perforation

True

Which fluoroquinolone ABx has a higher chance of causing tympanic membrane perforation?

Ofloxacin

what is the dosing for Cipro 0.2% for otitis externa?

0.25 mL in affected ear BID x 7 days

What is the dosing of Ofloxacin for patients aged 6 months - 13 years?

0.3%; 5 drops in affected ears QD x 7 days

what is the dosing of Ofloxacin for patients aged > 13 YO?

0.3%; 10 drops in affected ear QD x 7 days

what is the max number of days a patient can use an ABx + Steroid combo?

10 days

what is the dosing for Cipro 0.3% + Dexamethasone (Ciprodex) for otitis externa?

4 gtt in affected ear BID x 7 days

what is the dosing for Cipro 0.2% + Hydrocortisone 1% (Cipro HC) for otitis externa?

3 gtt in affected ear BID x 7 days

what are adverse reactions related to pharmacological therapies?

Pruritis, local reactions, dizziness, vertigo, dysgeusia

What drugs are ototoxic?

Aminoglycosides

how many days should patients limit their therapy of ototoxic agents?

10 days

what can be used as an antisepic prophylaxis for otitis externa?

Acetic acid 2%

T or F:

Antiseptics can be used in patients with known or suspected perforated tympanic membrane

False

How long should patients abstain from water activities if they have otitis externa?

7 - 10 days