Otitis externa

Acute otitis externa (AOE) is a diffuse inflammation of the external ear canal that is most commonly caused by Pseudomonas aeruginosa and Staphylococcus aureus.

Presents with rapid onset of ear pain, tenderness, itching, aural fullness, and hearing loss.

More common in children and young adults.

Fungal otitis externa is a fungal infection of the external ear caused by molds and yeasts, which presents in a similar way to acute bacterial otitis externa.

Necrotizing otitis externa infection (also called malignant otitis externa) involves skin and soft tissue of the external auditory canal and bone tissue of the temporal bone.

Treatment of the uncomplicated form is cleaning of the ear canal and application of topical anti-infective agents. Oral antibiotics may be required for patients with diabetes, those who are immunocompromised, or those who do not respond to initial topical treatment. Necrotizing otitis externa is a medical emergency requiring prompt treatment with debridement of necrotic tissue and oral or intravenous antibiotics.

AOE is defined as diffuse inflammation of the external ear canal, which may also involve the pinna or tympanic membrane.[1]Rosenfeld RM, Schwartz SR, Cannon CR, et al. American Academy of Otolaryngology-Head and Neck Surgery Foundation. Clinical practice guideline: acute otitis externa. Otolaryngol Head Neck Surg. 2014 Feb;150(1 suppl):S1-24. [Erratum in: Otolaryngol Head Neck Surg. 2014 Mar;150(3):504]. https://aao-hnsfjournals.onlinelibrary.wiley.com/doi/10.1177/0194599813517083 http://www.ncbi.nlm.nih.gov/pubmed/24491310?tool=bestpractice.com It is a form of cellulitis that involves the skin and subdermis of the external auditory canal, with acute inflammation and variable edema.[1]Rosenfeld RM, Schwartz SR, Cannon CR, et al. American Academy of Otolaryngology-Head and Neck Surgery Foundation. Clinical practice guideline: acute otitis externa. Otolaryngol Head Neck Surg. 2014 Feb;150(1 suppl):S1-24. [Erratum in: Otolaryngol Head Neck Surg. 2014 Mar;150(3):504]. https://aao-hnsfjournals.onlinelibrary.wiley.com/doi/10.1177/0194599813517083 http://www.ncbi.nlm.nih.gov/pubmed/24491310?tool=bestpractice.com It is most commonly caused by bacterial infection with Pseudomonas aeruginosa or Staphylococcus aureus.[1]Rosenfeld RM, Schwartz SR, Cannon CR, et al. American Academy of Otolaryngology-Head and Neck Surgery Foundation. Clinical practice guideline: acute otitis externa. Otolaryngol Head Neck Surg. 2014 Feb;150(1 suppl):S1-24. [Erratum in: Otolaryngol Head Neck Surg. 2014 Mar;150(3):504]. https://aao-hnsfjournals.onlinelibrary.wiley.com/doi/10.1177/0194599813517083 http://www.ncbi.nlm.nih.gov/pubmed/24491310?tool=bestpractice.com 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]Rosenfeld RM, Schwartz SR, Cannon CR, et al. American Academy of Otolaryngology-Head and Neck Surgery Foundation. Clinical practice guideline: acute otitis externa. Otolaryngol Head Neck Surg. 2014 Feb;150(1 suppl):S1-24. [Erratum in: Otolaryngol Head Neck Surg. 2014 Mar;150(3):504]. https://aao-hnsfjournals.onlinelibrary.wiley.com/doi/10.1177/0194599813517083 http://www.ncbi.nlm.nih.gov/pubmed/24491310?tool=bestpractice.com [Figure caption and citation for the preceding image starts]: Diagram of acute otitis externaCreated by the BMJ Knowledge Centre [Citation ends].