II. Epidemiology
- Bacterial Infection causes majority of Otitis Externa cases
III. Etiology
- Most common- Pseudomonas Aeruginosa (50% of cases)- More common in Diabetes Mellitus
- See Malignant External Otitis
 
- Staphylococcus Aureus
- Proteus
- Escherichia coli
 
- Pseudomonas Aeruginosa (50% of cases)
- Atypical Bacteria- Mycobacteria- Chronic Granulomatous and ulcerative canal lesions
 
- Mycoplasma- Bullous lesions on Tympanic Membrane
 
 
- Mycobacteria
IV. Findings: Signs and Symptoms
- See Otitis Externa
- More severe than other forms of Otitis Externa
- Significant canal swelling
- Fever (rarely over 38.3 C or 101.0 F)
- Lymphadenopathy anterior to tragus
V. Management: General
- See Otitis Externa (includes Ear toilet measures)
- 
                          General measures- Ear cleaning and Debridement is paramount
- Consider ear wick (see Otitis Externa)
- Oral Analgesics (e.g. Ibuprofen or Acetaminophen)
- Topical Analgesics (e.g. Aurodex) are no longer available in the U.S.
 
- Use caution if possible Tympanic Membrane Rupture (or PE Tubes)- Do not irrigate- Manual Cerumen Removal only
- Ear Suction is typically not recommended outside ENT use (risk of middle ear Trauma)
 
- Use only agents safe in Tympanic Membrane Rupture- See Quinolones listed below
- Low pH preparations are preferred
- Concurrent Topical Corticosteroid is preferred- May coadminister ophthalmic Dexamethasone drops with non-steroid Antibiotic drops
 
- Ofloxacin 0.3% otic drops
- Ciprofloxacin 0.3% eye drops (ciloxan)- Ciprofloxacin 0.3% also available with Corticosteroid (Ciprodex otic)
- Do NOT use cipro HC (not sterile)
 
 
- Avoid ototoxic preparations- Neomycin or polymixin agents (e.g. cortisporin)
- Aminoglycosides (e.g. Gentamicin, Tobramycin)
- Acetic acid
- Cortisporin (including suspension as of 2014)
 
 
- Do not irrigate
- Otitis Externa Topical Medications- See Ear Canal Instillation for topical otic medication instillation
- Treatment course- Use for 3 days after symptoms resolve
- Typical treatment course 7 to 10 days
 
- Ear Canal Acidification (as effective as Cortisporin)- Acetic acid Otic Solution 2% (VoSol)- Acetic acid with Hydrocortisone (Vosol HC)
- Acetic acid with Aluminum acetate (Otic Domeboro)
 
- Homemade- 2% Otic Acetic Acid (white vinegar) drops tid OR
- 1:1 mix of 5% acetic acid and Rubbing Alcohol tid
 
 
- Acetic acid Otic Solution 2% (VoSol)
- Neomycin and Polymixin Antibiotic Preparations- Risk of Neomycin-induced Contact Dermatitis: 5-18%
- Neomycin with Polymixin B and Hydrocortisone- Cortisporin Otic Suspension 4 drops in ear tid
 
- Neomycin with Thonzonium and Hydrocortisone- Coly-Mycin S
 
- Polymyxin B and Hydrocortisone (Otobiotic)
 
- Quinolone Preparations- See below
 
 
- Resistant Cases (or allergy to neomycin)- Treatment Course: 10 - 14 days
- Quinolone Preparations (instill twice daily)- Ofloxacin 0.3% Otic Solution (Floxin Otic)
- Ofloxacin 0.3% ophthalmic solution (Ocuflox)
- Ciprofloxacin 0.3% ophthalmic solution (Ciloxan)
- Ciprofloxacin 0.2% with Hydrocortisone 1% suspension (not sterile)
- Ciprofloxacin 0.3% with Dexamethasone 0.1% (cipro-dex)
 
- Aminoglycoside Preparations (ophthalmic solutions)- Gentamicin sulfate 0.3% (Garamycin)
- Tobramycin sulfate 0.3% (Tobrex)
 
 
- Systemic Antibiotic Indications- Otitis Media
- Persistent Otitis Externa or Periauricular Cellulitis- Severe pain with fever over 101 F
- First Generation Cephalosporin (Keflex, Duricef)
 
- Necrotizing Otitis Externa (Malignant Otitis Externa)
- Immunocompromised condition (e.g. Diabetes Mellitus)
 
VI. Management: Refractory course
- Expect improvement in responding cases within 72 hours
- Consider alternative diagnosis (See Otitis Externa)
- Consider Consultation with Otolaryngology
VII. Complications
- Necrotizing Otitis Externa
- Periauricular Cellulitis
- Ear Canal Furuncle
- Temporal Bone Infection <0.5% risk- Requires aggresive care (Life-threatening)
 
VIII. Prevention
- See Otitis Externa
IX. References
- Orman and Finley in Herbert (2018) EM:Rap 18(1): 21
- (2014) Presc Lett 21(6): 35-36
- Bojrab (1996) Otolaryngol Clin North Am 29:761-82 [PubMed]
- Halpern (1999) J Am Board Fam Pract 12(1):1-7 [PubMed]
- Jackson (2023) Am Fam Physician 107(2): 145-51 [PubMed]
- Mirza (1996) Postgrad Med 99:153-8 [PubMed]
- Rosenfeld (2006) Otolaryngol Head Neck Surg 134 (4 suppl): S4-23 [PubMed]
- Sander (2001) Am Fam Physician 63:927-42 [PubMed]
- Schaefer (2012) Am Fam Physician 86(11): 1055-61 [PubMed]
- Selesnick (1994) Am J Otol 15:408-12 [PubMed]
