When should I consider prescribing antibiotics for otitis externa, and which agents are preferred?

When to consider prescribing antibiotics for otitis externa: Consider prescribing oral antibiotics only if the person is immunocompromised, has severe infection, or if the infection has spread beyond the external ear canal to adjacent tissues. Oral antibiotics are generally not recommended for uncomplicated acute otitis externa due to limited efficacy compared to topical treatments and increased risk of adverse effects and bacterial resistance. Arrange follow-up if symptoms do not improve within 48–72 hours of starting treatment, if symptoms persist beyond 2 weeks, or if there is cellulitis spreading beyond the ear canal.

Preferred antibiotic agents: First-line treatment is topical antibiotic ear drops, which provide high local drug concentration and improved efficacy. Antibiotic eardrops containing quinolones (such as ciprofloxacin), aminoglycosides (such as neomycin), or polymyxins (such as polymyxin B) have been shown to provide more rapid symptom relief and lower recurrence rates compared with placebo. Avoid ototoxic topical preparations (e.g., aminoglycosides or alcohol-containing drops) if there is tympanic membrane perforation. The addition of topical corticosteroids may be considered to reduce inflammation and pain, although evidence is inconsistent. For suspected fungal infection, topical antifungals like clotrimazole or acetic acid 2% ear drops may be used.