Acute otitis externa, also known as swimmer's ear, is an inflammatory condition affecting the external ear canal that is a common problem encountered in primary care offices. This article provides a brief update and summary of the best available patient-oriented evidence for treating acute otitis externa.

Epidemiology

• Acute otitis externa occurs in all age groups. An estimated 10% of people will develop acute otitis externa during their lifetime.¹ Younger age groups are most commonly affected, with decreased incidence as one ages (Table 1²).

• Acute otitis externa is responsible for more than 500,000 emergency department visits each year.³

• Risk factors for acute otitis externa are summarized in Table 2,⁴ with the most common factor being swimming.^4,5

Diagnosis

• The clinical diagnosis of acute otitis externa is based on symptoms of inflammation in the ear canal. Criteria proposed by the American Academy of Otolaryngology–Head and Neck Surgery to aid in diagnosis are listed in Table 3.⁵ Figure 1 and Figure 2 demonstrate the redness and edema of the canal seen with acute otitis externa.⁴

• The most common symptom is pain in the tragus, pinna, or both,⁶ which is disproportionate to what is expected on visual inspection.⁵ Other causes that may be included in the differential diagnosis of ear canal inflammation are listed in Table 4.⁴

• Physicians should review the presenting symptom onset and exposure to water (e.g., swimming) as well as any trauma to the canal and history of other skin conditions such as eczema, psoriasis, or seborrhea. Additional history should include prior surgeries, radiation therapy, or history of systemic illnesses such as diabetes mellitus, or conditions that may predispose to immune suppression.

• The pinna, tragus, ear canal, and regional lymph nodes should be examined. Use of pneumatic otoscopy is recommended to help differentiate acute otitis externa from otitis media and to assist in determining that the tympanic membrane is intact without perforation because these determinations have implications for treatment options.⁴ If a perforation has occurred, the medications that can be used topically are limited.

• An examination for signs of cellulitis or extension beyond the ear canal should be performed.

• Cultures of otorrhea are usually not performed because most cases of acute otitis externa are caused by bacterial infection,⁷ predominantly with Pseudomonas aeruginosa or Staphylococcus aureus.

Treatment

MANAGEMENT OF PAIN

• Per 2014 guidelines from the American Academy of Otolaryngology–Head and Neck Surgery,⁵ which were endorsed by the American Academy of Family Physicians and reaffirmed in 2019,⁸ treatment for acute otitis externa should include an assessment of pain. Using analgesics as a mainstay of therapy to help in the management of acute otitis externa allows for increased comfort and more rapid return to normal activities.⁹ Figure 3 presents an algorithm for treatment.⁵

• Analgesics that can provide relief include acetaminophen, nonsteroidal anti-inflammatory drugs, or, in rare cases, the addition of a short-term opioid. Based on expert opinion, fixed dosing intervals are recommended rather than as-needed dosing.⁹

• Available topical analgesics are limited to over-the-counter homeopathic medications for which there is no evidence of benefit. The use of otic benzocaine with or without antipyrine was withdrawn from the U.S. market in 2015.¹⁰ Concerns with the use of topical analgesics include the potential dilution of antibiotic drops and unknown ototoxicity if there is a perforated tympanic membrane.