Summary
Definition
AOE is defined as diffuse inflammation of the external ear canal, which may also involve the pinna or tympanic membrane.[1] It is a form of cellulitis that involves the skin and subdermis of the external auditory canal, with acute inflammation and variable edema.[1] It is most commonly caused by bacterial infection with Pseudomonas aeruginosa or Staphylococcus aureus.[1] National guidelines state that a diagnosis of AOE requires the presence of rapid onset (generally within 48 hours) of symptoms within the past 3 weeks, coupled with signs of ear canal inflammation.[1][Figure caption and citation for the preceding image starts]: Diagram of acute otitis externaCreated by the BMJ Knowledge Centre [Citation ends].
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 (necrotizing otitis externa)
Other diagnostic factors
- otorrhea
- aural fullness
- itching
- decreased hearing
- pain intensified by jaw motion
- erythematous tympanic membrane
- cellulitis of the pinna and adjacent skin
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
Diagnostic tests
Tests 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)
Treatment algorithm
Contributors
Authors
Soha Ghossaini, MD, FACS
Otology-Neurotology
ENT and Allergy Associates LLP
Flushing
New York
NY
Disclosures
SG declares that she has no competing interests.
Acknowledgements
We would like to acknowledge our ENT expert panel member, Dr Lawrence Lustig, for his contribution to this topic. Dr Lustig declares that he 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
Dallas
TX
Disclosures
PSR has acted as a consultant to Alcon Laboratories, maker of Ciprodex®, which has 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 acute otitis externa. PSR is an author of references cited in this topic.
Anthony Wright, LLM, DM, FRCS
Emeritus Professor of Otolaryngology
UCL Ear Institute
London
UK
Disclosures
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
Bristol
UK
Disclosures
DAN declares that he has no competing interests.
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