Ear

Bacterial Otitis Externa

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Bacterial Otitis Externa

  • Epidemiology
  1. Bacterial Infection causes majority of Otitis Externa cases
  • Etiology
  1. Most common
    1. Pseudomonas aeruginosa (50% of cases)
      1. More common in Diabetes Mellitus
      2. See Malignant External Otitis
    2. Staphylococcus aureus
    3. Proteus
    4. Escherichia coli
  2. Atypical Bacteria
    1. Mycobacteria
      1. Chronic granulomatous and ulcerative canal lesions
    2. Mycoplasma
      1. Bullous lesions on Tympanic Membrane
  • Signs and Symptoms
  1. See Otitis Externa
  2. More severe than other forms of Otitis Externa
  3. Significant canal swelling
  4. Fever (rarely over 38.3 C or 101.0 F)
  5. Lymphadenopathy anterior to tragus
  • Management
  1. See Otitis Externa (includes Ear toilet measures)
  2. General measures
    1. Ear cleaning and debridement is paramount
    2. Consider ear wick (see Otitis Externa)
    3. Oral Analgesics (Ibuprofen or Tylenol)
    4. Topical Analgesics (e.g. Aurodex) may be used with caution (risk of Contact Dermatitis)
  3. Use caution if possible Tympanic Membrane Rupture (or PE Tubes)
    1. Do not irrigate (suction only)
    2. Use only agents safe in Tympanic Membrane Rupture
      1. See Quinolones listed below
      2. Concurrent Topical Corticosteroid is preferred
        1. May coadminister ophthalmic Dexamethasone drops with non-steroid antibiotic drops
      3. Ofloxacin 0.3% otic drops
      4. Ciprofloxacin 0.3% eye drops (ciloxan)
        1. Ciprofloxacin 0.3% also available with Corticosteroid (Ciprodex otic)
        2. Do NOT use cipro HC (not sterile)
    3. Avoid ototoxic preparations
      1. Neomycin or polymixin agents (e.g. cortisporin)
      2. Aminoglycosides (e.g. Gentamicin, Tobramycin)
      3. Acetic acid
      4. Cortisporin (including suspension as of 2014)
  4. Otitis Externa Topical Medications
    1. See Ear Canal Instillation for topical otic medication instillation
    2. Treatment course
      1. Use for 3 days after symptoms resolve
      2. Typical treatment course 7 to 10 days
    3. Ear Canal Acidification (as effective as Cortisporin)
      1. Acetic acid Otic Solution 2% (VoSol)
        1. Acetic acid with Hydrocortisone (Vosol HC)
        2. Acetic acid with Aluminum acetate (Otic Domeboro)
      2. Homemade
        1. 2% Otic Acetic Acid (white vinegar) drops tid OR
        2. 1:1 mix of 5% acetic acid and Rubbing Alcohol tid
    4. Antibiotic preparations
      1. Risk of Neomycin-induced Contact Dermatitis: 5-18%
      2. Neomycin with Polymixin B and Hydrocortisone
        1. Cortisporin Otic Suspension 4 drops in ear tid
      3. Neomycin with Thonzonium and Hydrocortisone
        1. Coly-Mycin S
      4. Polymyxin B and Hydrocortisone (Otobiotic)
  5. Resistant Cases (or allergy to neomycin)
    1. Treatment Course: 10 - 14 days
    2. Quinolone Preparations (instill twice daily)
      1. Ofloxacin 0.3% Otic Solution (Floxin Otic)
      2. Ofloxacin 0.3% ophthalmic solution (Ocuflox)
      3. Ciprofloxacin 0.3% ophthalmic solution (Ciloxan)
      4. Ciprofloxacin 0.3% with Hydrocortisone suspension
      5. Ciprofloxacin 0.3% with Dexamethasone (cipro-dex)
    3. Aminoglycoside Preparations (ophthalmic solutions)
      1. Gentamicin sulfate 0.3% (Garamycin)
      2. Tobramycin sulfate 0.3% (Tobrex)
  6. Systemic antibiotic Indications
    1. Otitis Media
    2. Persistent Otitis Externa or Periauricular Cellulitis
      1. Severe pain with fever over 101 F
      2. First generation Cephalosporin (Keflex, Duricef)
    3. Necrotizing Otitis Externa (Malignant Otitis Externa)
    4. Immunocompromised condition (e.g. Diabetes Mellitus)
  • Management
  • Refractory course
  1. Consider alternative diagnosis (See Otitis Externa)
  2. Consider Consultation with Otolaryngology
  • Complications
  1. Necrotizing Otitis Externa
  2. Periauricular Cellulitis
  3. Ear Canal Furuncle
  4. Temporal Bone infection <0.5% risk
    1. Requires aggresive care (Life-threatening)
  • Prevention