Otitis externa

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Background

Ear anatomy
  • Inflammation of the external auditory canal (EAC), often due to bacterial infection
  • Common in all age groups, but in the US commonly present in childhood [1]
  • In rare cases, immunocompromised patients may have fungal otitis external from Aspergillus or Candida

Microbiology

Risk Factors

  • Swimming
  • Excessive Q-tip (or other instrument) use

Clinical Features

Mild otitis externa
Severe otitis externa
Rapid onset (generally within 48 hours) in the past 3 weeks, AND.[2]
  • Symptoms
  • Signs
    • Tenderness of the pinaa and/or tragus
    • Diffuse ear canal edema, erythema, and possibly debris
    • Tympanic membrane may not be visualized due to EAC edema
    • Otorrhea
    • Local lymphadenitis
    • Tympanic membrane erythema, or
    • Cellulitis of the pinna and adjacent skin

Differential Diagnosis

Ear Diagnoses

External

Internal

Inner/vestibular

Evaluation

  • Normally clinical
    • Routine labwork or EAC cultures typically not necessary

Management

Hygiene

  • Clean the ear canal (Grade C)
    • Cerumen wire loop or cotton swab usually works best
    • 1:1 dilution of 3% hydrogen peroxide if tympanic membrane is visible and intact
    • Acetic acid wash for debridement of dead skin
  • Place a wick if the ear canal is fully obstructed
    • Instruct patient that the wick should fall out spontaneously in 3 days as swelling decreases; a clinician may remove it otherwise

Analgesia

Prevention

  • Keep ear canal dry
    • Abstain from water sports for 7-10 days
  • Counsel patient to avoid Q-tip or other foreign objects in the ear

Antibiotics

  1. Ofloxacin (Floxin otic): 5 drops in affected ear BID x 7 days[2]
    • Safe with perforations
  2. Ciprofloxacin-hydrocortisone (Cipro HC): 3 drops in affected ear BID x 7 days
    • Contains hydrocortisone to promote faster healing
    • Not recommended for perforation since non-sterile preparation
  3. Ciprofloxacin-dexamthasone (Ciprodex): 4 drops in affected ear BID x 7 days
    • Similar to Cipro HC but safe for perforations
    • Often more expensive
  4. Cortisporin otic (neomycin/polymixin B/hydrocortisone): 4 drops in ear TID-QID x 7days
    • Use suspension (NOT solution) if possibility of perforation
    • Animal studies suggest possible toxicity from the neomycin although rigorous data is lacking[3]
  • Instruct the patient to instill the medication into the ear while laying on their side and hold position for 3-5 minutes
    • Typically a least 4 drops are needed to fill the entire ear canal
  • Consider systemic antibiotics in specific cases:
    • Immunosuppressed (HIV, poorly controlled diabetes, chemotherapy, chronic high dose corticosteroid use, immunosuppressive drugs, neutropenia) give systemic antibiotic (ciprofloxacin or ofloxacin) [4]
    • If TMs are able to be visualized and suggest otitis media
    • If there is a suspicion of malignant otitis externa

Disposition

  • Discharge
    • Follow up with PCP or ENT in 1-2 weeks for patients with moderate disease

See Also

External Links

References

  1. Beers SL, Abramo TJ. Otitis externa review. Pediatr Emerg Care. 2004 Apr;20(4):250-6. doi: 10.1097/01.pec.0000121246.99242.f5. PMID: 15057182.
  2. 2.0 2.1 Clinical Practice Guideline: Acute Otitis Externa Executive Summary. Otolaryngology -- Head and Neck Surgery 2014 150: 161 DOI: 10.1177/0194599813517659 PDF
  3. Wright, C. et al. Ototoxicity of neomycin and polymyxin B following middle ear application in the chinchilla and baboon. Am J Otol. 1987 Nov;8(6):495-9.
  4. Santos F, Selesnick SH, Gurnstein E. Diseases of the External Ear. In:Current Diagnosis and Treatment in Otolaryngology: Head and Neck Surgery, Lalwani AK (Ed), Lange Medical Books/McGraw-Hill, New York 2004.