Otitis externa

Last reviewed: 24 Feb 2023
Last updated: 02 Sep 2021



History and exam

Key diagnostic factors

  • ear pain
  • tenderness over the tragus, pinna, or both
  • ear canal swelling and erythema
  • granulation tissue in the ear canal (malignant otitis externa)
More key diagnostic factors

Other diagnostic factors

  • otorrhea
  • aural fullness
  • itching
  • decreased hearing
  • pain intensified by jaw motion
  • erythematous tympanic membrane
  • cellulitis of the pinna and adjacent skin
Other diagnostic factors

Risk factors

  • external auditory canal obstruction
  • high environmental humidity
  • warmer environmental temperatures
  • swimming
  • local trauma
  • chemical irritants
  • allergy
  • skin disease
  • diabetes
  • immunocompromised
  • prolonged use of topical antibacterial agents
More risk factors

Diagnostic investigations

1st investigations to order

  • pneumatic otoscopy
  • tympanometry
More 1st investigations to order

Investigations to consider

  • ear culture
  • microscopy of exudate/debris from ear canal
  • CT scan of the temporal bone with intravenous contrast
  • MRI of the brain and internal auditory canals (with and without gadolinium)
  • erythrocyte sedimentation rate (ESR)
More investigations to consider

Treatment algorithm






Soha Ghossaini, MD, FACS


Ear, Nose and Throat Associates of New York


New York



SG declares that she has no competing interests.

Peer reviewers

Peter S. Roland, MD

Professor Neurological Surgery

Chief of Pediatric Otology

Otolaryngology Head and Neck Surgery

UT Southwestern Medical Center




PSR has acted as a consultant to Alcon laboratories, makers of Ciprodex®, who have provided compensation to the University of Texas Southwestern Medical Center Department of Otolaryngology Head and Neck Surgery. PSR has received compensation for speaking and for organizing educational events. PSR is co-author of the American Academy of Head and Neck Surgery's practice guideline for AOE. PSR is an author of references cited in this topic.

Anthony Wright, LLM, DM, FRCS

Emeritus Professor of Otolaryngology

UCL Ear Institute




AW declares that he has no competing interests.

Desmond A. Nunez, MD, FRCS(ORL)

Director ENT Unit

North Bristol NHS Trust

Honorary Reader in Otolaryngology

University of Bristol




DAN declares that he has no competing interests.

  • Otitis externa images
  • Differentials

    • Acute otitis media
    • Furunculosis
    • Contact dermatitis of the ear canal
    More Differentials
  • Guidelines

    • Clinical practice guideline: acute otitis externa
    • Practice point: acute otitis externa
    More Guidelines
  • Patient leaflets

    Outer ear infection

    Ear infection in children: questions to ask your doctor

    More Patient leaflets
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