External Otitis (Swimmer's Ear)

How external otitis develops

The ear canal is lined with thin skin and protected by earwax, which is slightly acidic and water-repellent. When the canal stays wet, or the skin is scratched, this barrier breaks down and bacteria from the environment multiply. The most common organisms are Pseudomonas aeruginosa and Staphylococcus aureus. Fungal infection (otomycosis) is less common and more likely after long antibiotic drop use or in humid climates.

Causes and risk factors

• swimming, especially in lakes and rivers, and frequent showering
• humid weather and sweating
• cleaning ears with cotton swabs, fingers or objects
• hearing aids, earbuds and earplugs
• skin conditions such as eczema, psoriasis and seborrheic dermatitis
• narrow or hairy ear canals
• hair products, dyes and sprays
• removing all earwax

Symptoms

• ear pain, often severe, worse when chewing or moving the outer ear
• itching in the ear canal
• redness and swelling of the canal
• discharge, which may be clear, yellow or green and smelly
• a feeling of fullness and muffled hearing
• tender, swollen lymph nodes in front of or behind the ear
• fever is uncommon

Swimmer's ear vs middle ear infection

Diagnosis

A doctor examines the ear with an otoscope, looking for a red, swollen canal and debris, and checks the eardrum if it is visible. Pain on pulling the ear or pressing the tragus is typical. A swab is taken for recurrent, severe or non-responding cases. Imaging (CT or MRI) is used if necrotizing otitis externa is suspected.

Treatment

Ear drops

• Antibiotic or antibiotic-steroid drops (such as ciprofloxacin with dexamethasone, or ofloxacin) for 7 days, or 3 to 4 days after symptoms resolve, up to 10 days.
• Use non-ototoxic drops (fluoroquinolones) if the eardrum may be perforated or you have ear tubes.
• Oral antibiotics are usually not needed unless infection spreads beyond the canal or you have diabetes or weakened immunity.
• Antifungal drops for otomycosis.

How to use ear drops

1. Warm the bottle in your hand for a few minutes.
2. Lie with the affected ear up.
3. Put in the prescribed number of drops, then gently pump the tragus to help them flow.
4. Stay lying for 3 to 5 minutes.

Other measures

• Ear cleaning (aural toilet): a doctor may gently clean debris so drops can reach the skin.
• Ear wick: a small sponge placed in a very swollen canal to draw drops in.
• Pain relief: acetaminophen (paracetamol) or ibuprofen, following the label.
• Keep the ear dry: avoid swimming for 7 to 10 days; use a cotton ball with petroleum jelly in the ear while showering.
• Avoid hearing aids and earbuds until healed.

Necrotizing (malignant) otitis externa

A rare but serious infection that spreads from the ear canal into the bone of the skull base. It mainly affects older adults with diabetes or weakened immunity. Warning signs are severe, persistent ear pain (often worse at night), discharge, granulation tissue in the canal, and later facial weakness or other cranial nerve problems. It needs imaging and long courses of IV or oral antibiotics. See malignant otitis externa.

Prevention

• Dry ears after swimming: tilt the head, pull the earlobe in different directions, and use a hair dryer on the lowest setting held at arm's length.
• Use swim earplugs or a swim cap if prone to infections.
• Over-the-counter drying drops (often containing alcohol and acetic acid) after swimming can help, but not if you have ear tubes or a perforated eardrum.
• Do not put cotton swabs or objects in your ears.
• Leave earwax alone unless it is blocking hearing; see earwax impaction.

Frequently asked questions

How do I know if I have swimmer's ear?

Swimmer's ear usually causes ear pain that gets worse when you pull your earlobe or press the flap in front of the ear canal, along with itching, redness, discharge and muffled hearing. It often follows swimming or using cotton swabs.

How long does swimmer's ear last?

With antibiotic ear drops, pain usually improves within 2 to 3 days and the infection clears in 7 to 10 days. If symptoms are not better after 48 to 72 hours, see your doctor again.

Can swimmer's ear go away on its own?

Very mild cases may settle, but most need antibiotic ear drops. Untreated infections can become more painful, spread to the outer ear or, rarely in high-risk people, the skull bone. Keeping the ear dry speeds healing.

Can I swim with swimmer's ear?

It is best to avoid swimming for 7 to 10 days while the canal heals. If you must swim, a well-fitting earplug and a swim cap reduce water entry, but healing may be slower.

What is the difference between otitis externa and otitis media?

Otitis externa is an infection of the outer ear canal, treated with ear drops. Otitis media is an infection of the middle ear behind the eardrum, common in young children after colds, and is treated with pain relief and sometimes oral antibiotics.