Acute Otitis Externa

Key facts

• Acute otitis externa is an infection of the skin lining the outer ear canal, often called swimmer's ear because trapped water softens the skin and lets bacteria take hold.
• It causes pain that typically worsens when you touch or pull the outer ear, along with itching, a feeling of fullness, and sometimes a clear or yellowish discharge.
• Most cases are caused by bacteria, especially Pseudomonas aeruginosa or Staphylococcus aureus.
• Standard treatment is antibiotic ear drops combining ciprofloxacin, to clear the infection, with dexamethasone, to reduce inflammation and ease pain quickly.
• See a doctor promptly if pain is severe, hearing is muffled, or symptoms haven't improved after a few days of treatment.

What's happening

Acute otitis externa is an infection of the skin lining the outer ear canal. It's often called swimmer's ear because water trapped in the canal softens the skin and disrupts its natural defences, letting bacteria take hold. The result is pain that typically worsens when the outer ear is touched or pulled, along with itching, a feeling of fullness, and sometimes a clear or yellowish discharge.

What causes it

The vast majority of cases are caused by bacteria, most often Pseudomonas aeruginosa or Staphylococcus aureus. Frequent water exposure, humid conditions, and using cotton buds or other objects that scratch the canal all raise the risk.

How it's treated

Antibiotic ear drops combining ciprofloxacin, to clear the bacterial infection, with dexamethasone, to reduce inflammation and ease pain quickly, are a standard approach. Keeping the canal dry and avoiding cotton buds speeds recovery; a clean cotton plug worn while showering can help.

When to see a doctor

See a doctor promptly if pain is severe, hearing is muffled, or symptoms haven't improved after a few days of treatment, since infection occasionally spreads beyond the canal.

This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.