What is the treatment for ear infections in adults?

Treatment of Ear Infections in Adults

For uncomplicated otitis externa (the most common adult ear infection), use topical antibiotic drops with or without corticosteroids as first-line therapy; reserve systemic antibiotics exclusively for acute otitis media or when infection extends beyond the ear canal. 1, 2

Identify the Type of Ear Infection

Otitis Externa (Swimmer's Ear)

• Most common ear infection in adults with 10% lifetime incidence 1, 2
• Key diagnostic feature: tenderness when moving the tragus or pinna 2
• Look for ear pain, itching, canal swelling/redness, discharge, often after swimming or ear trauma 2
• Caused primarily by Pseudomonas aeruginosa and Staphylococcus aureus 1

Acute Otitis Media

• Less common in adults than children 1
• Involves middle ear space behind tympanic membrane
• Caused by Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis 1

Assess Critical Modifying Factors Before Treatment

Check for these conditions that fundamentally change management:

• Tympanic membrane perforation or tympanostomy tubes: Requires non-ototoxic preparations (avoid aminoglycosides) 2, 3
• Diabetes or immunocompromised state: Higher risk for necrotizing otitis externa and fungal infections; may require systemic antibiotics even for otitis externa 1, 2
• Prior radiotherapy: May require systemic antimicrobials 1

First-Line Treatment for Uncomplicated Otitis Externa

Topical antibiotic drops ± corticosteroids 1, 2

• Topical therapy delivers 100-1000 times higher antibiotic concentration than systemic therapy 1, 2
• Combination antibiotic-corticosteroid drops provide faster pain relief 1, 2
• Ofloxacin otic 0.3% is FDA-approved for otitis externa in adults, covering E. coli, Pseudomonas aeruginosa, and Staphylococcus aureus 3
• Do NOT prescribe oral antibiotics for uncomplicated otitis externa—this increases antibiotic resistance without clinical benefit 2

Pain Management for All Ear Infections

• Offer systemic analgesics (acetaminophen or ibuprofen) to all patients based on pain severity 1, 2
• Topical analgesics may reduce pain within 10-30 minutes, though evidence quality is limited 1, 2
• Pain management is especially critical during the first 24 hours 1

Treatment for Acute Otitis Media

Systemic antibiotics are required 1, 2

First-line: Amoxicillin-clavulanate 1, 2

• Standard dose: 1.75 g amoxicillin/250 mg clavulanate per day for mild-moderate disease 1, 2
• High-dose: 4 g amoxicillin/250 mg clavulanate per day for recent antibiotic exposure or moderate disease 1
• Covers S. pneumoniae (including penicillin-intermediate strains), β-lactamase-producing H. influenzae, and β-lactamase-producing M. catarrhalis 1
• Predicted clinical efficacy: 90-92% 1

For penicillin allergy:

• Respiratory fluoroquinolones (levofloxacin, moxifloxacin): 90-92% clinical efficacy 1
• Azithromycin: Lower efficacy with 20-25% bacteriologic failure rates 1

When to Use Systemic Antibiotics

Systemic antibiotics are indicated for: 1, 2

• Confirmed acute otitis media
• Extension of infection beyond the ear canal
• Diabetes or immunocompromised patients (even with otitis externa)
• Suspected necrotizing otitis externa

Expected Timeline and Treatment Failure

Symptoms should improve within 48-72 hours 1, 2

If no improvement by 48-72 hours: 1, 2

• Reassess to confirm diagnosis and exclude other conditions
• Consider treatment failure, allergic contact dermatitis, fungal infection, or misdiagnosis
• For confirmed treatment failure, switch to a different antibiotic class rather than increasing dose 1
• Do not continue the same antibiotic beyond 72 hours without improvement 1
• Take bacterial or fungal culture if not already done 4

Critical Pitfalls to Avoid

• Never prescribe oral antibiotics for uncomplicated otitis externa—no clinical benefit and increases resistance 1, 2
• Missing necrotizing otitis externa in diabetic/immunocompromised patients—this is life-threatening and requires aggressive treatment with systemic antibiotics 2
• Failing to consider fungal infection when standard treatment fails 1
• Using ototoxic drops (aminoglycosides) when tympanic membrane is perforated 2, 3

When to Refer to Otolaryngology

Refer if: 2

• Symptoms persist beyond 7 days despite appropriate treatment
• Hearing loss develops or persists
• Excessive cerumen cannot be safely removed
• Recurrent infections occur