What is the diagnosis and treatment for otitis externa (inflammation of the external ear)?

From the Guidelines

Otitis externa, commonly known as swimmer's ear, is an infection of the ear canal that requires prompt treatment with topical antibiotic ear drops, such as ciprofloxacin/dexamethasone (Ciprodex) or ofloxacin (Floxin), applied 3-4 drops twice daily for 7-10 days, as recommended by the American Academy of Otolaryngology—Head and Neck Surgery Foundation 1.

Key Considerations

• Before application, the ear canal should be gently cleaned of debris to allow medication to penetrate effectively, using methods such as aural toilet with suction or dry mopping, but avoiding irrigation in patients with diabetes or immunocompromised states 1.
• For severe cases with significant swelling, an ear wick may be inserted by a healthcare provider to facilitate medication delivery.
• Oral analgesics like acetaminophen or ibuprofen can help manage pain, and patients should be advised to use pain medicine for relief in the first few days until the eardrops begin working 1.

Prevention Strategies

• Keep the ear dry by avoiding swimming and using earplugs or cotton balls coated with petroleum jelly when showering.
• Dry ears thoroughly after swimming using a hair dryer on low setting.
• Use over-the-counter drying agents containing acetic acid or alcohol after water exposure.
• Avoid insertion of objects into the ear canal.

High-Risk Patients

• Patients with diabetes or compromised immune systems should seek medical attention promptly as they're at higher risk for malignant otitis externa, a serious complication that can spread to surrounding tissues 1.
• These patients may require systemic antibiotics and should be managed with caution to avoid complications such as necrotizing otitis externa.

Treatment Outcomes

• The primary outcome considered in the treatment of otitis externa is clinical resolution of the infection, which implies resolution of all presenting signs and symptoms, such as pain, fever, and otorrhea 1.
• Additional outcomes considered include minimizing the use of ineffective treatments, eradicating pathogens, and maximizing the health-related quality of life of individuals afflicted with otitis externa.

From the FDA Drug Label

Ciprofloxacin otic solution, 0.2% is a quinolone antimicrobial indicated for the treatment of acute otitis externa due to susceptible isolates of Pseudomonas aeruginosa or Staphylococcus aureus. The treatment of otitis externa with ciprofloxacin otic solution, 0.2% is indicated for acute cases due to susceptible isolates of Pseudomonas aeruginosa or Staphylococcus aureus 2.

• The solution should be instilled into the affected ear twice daily for 7 days.
• Key points to consider:
  • Contraindications: history of hypersensitivity to ciprofloxacin.
  • Warnings and precautions: otic use only, hypersensitivity, growth of resistant organisms with prolonged use, and lack of clinical response.
• Clinical efficacy was demonstrated in a randomized, multi-center, evaluator-blinded study, with a clinical cure rate of 70% at the end of a 7-day treatment 2.

From the Research

Causes and Symptoms of Otitis Externa

• Otitis externa is most commonly caused by infection (usually bacterial, although occasionally fungal) 3
• It may also be associated with a variety of noninfectious systemic or local dermatologic processes 3
• The most characteristic symptom is discomfort that is limited to the external auditory canal 3
• The most characteristic signs are erythema and swelling of the canal with variable discharge 3

Precipitants and Prevention of Otitis Externa

• Excessive moisture and trauma are the two most common precipitants of otitis externa 3
• Avoidance of these precipitants is the cornerstone of prevention 3
• Thorough cleansing of the canal is essential for diagnosis and treatment, but flushing should be avoided 3
• Acidification with a topical solution of 2 percent acetic acid combined with hydrocortisone for inflammation is effective treatment in most cases 3
• Other prophylactic measures such as drying the ears with a hair dryer and avoiding manipulation of the external auditory canal may help prevent recurrence 3

Treatment of Otitis Externa

• Topical non-antibiotic treatments, such as antiseptics and steroids, are effective for the management of acute otitis externa 4
• Ciprofloxacin, an antibiotic, is also effective in treating otitis externa, especially when combined with fluocinolone acetonide 5, 6, 7
• A systematic review and meta-analysis found no significant differences in cure rates between antiseptic and steroid monotherapies and topical antibiotic agents 4
• Ciprofloxacin plus fluocinolone acetonide otic solution was found to be efficacious and safe in treating acute otitis externa, but did not demonstrate superiority over ciprofloxacin or fluocinolone acetonide otic solutions alone 6

Microbiological Efficacy of Treatments

• Ciprofloxacin has been shown to have high in vitro activity against Pseudomonas aeruginosa, a common pathogen in otitis externa 5, 7
• The combination of ciprofloxacin and fluocinolone acetonide was found to have a statistically superior sustained microbiological response compared to ciprofloxacin or fluocinolone acetonide alone 6
• The microbiological outcome of treatment with ciprofloxacin plus fluocinolone acetonide was also found to be superior to that of fluocinolone acetonide alone 6