Overview

Swimmer's ear is an infection in the outer ear canal, which runs from your eardrum to the outside of your head. It's often brought on by water that remains in your ear after swimming, creating a moist environment that aids bacterial growth.

Putting fingers, cotton swabs or other objects in your ears also can lead to swimmer's ear by damaging the thin layer of skin lining your ear canal.

Swimmer's ear is also known as otitis externa. The most common cause of this infection is bacteria invading the skin inside your ear canal. Usually you can treat swimmer's ear with eardrops. Prompt treatment can help prevent complications and more-serious infections.

Symptoms

Swimmer's ear symptoms are usually mild at first, but they may get worse if your infection isn't treated or spreads. Doctors often classify swimmer's ear according to mild, moderate and advanced stages of progression.

Mild signs and symptoms

  • Itching in your ear canal
  • Slight redness inside your ear
  • Mild discomfort that's made worse by pulling on your outer ear (pinna, or auricle) or pushing on the little "bump" (tragus) in front of your ear
  • Some drainage of clear, odorless fluid

Moderate progression

  • More intense itching
  • Increasing pain
  • More extensive redness in your ear
  • Excessive fluid drainage
  • Discharge of pus
  • Feeling of fullness inside your ear and partial blockage of your ear canal by swelling, fluid and debris
  • Decreased or muffled hearing

Advanced progression

  • Severe pain that may radiate to your face, neck or side of your head
  • Complete blockage of your ear canal
  • Redness or swelling of your outer ear
  • Swelling in the lymph nodes in your neck
  • Fever

When to see a doctor

Contact your doctor if you're experiencing any signs or symptoms of swimmer's ear, even if they're mild.

Call your doctor immediately or visit the emergency room if you have:

  • Severe pain
  • Fever

Causes

Swimmer's ear is an infection that's usually caused by bacteria commonly found in water and soil. Infections caused by a fungus or a virus are less common.

Your ear's natural defenses

Your outer ear canals have natural defenses that help keep them clean and prevent infection. Protective features include:

  • Glands that secrete a waxy substance (cerumen). These secretions form a thin, water-repellent film on the skin inside your ear. Cerumen is also slightly acidic, which helps further discourage bacterial growth. In addition, cerumen collects dirt, dead skin cells and other debris and helps move these particles out of your ear. The waxy clump that results is the familiar earwax you find at the opening of your ear canal.
  • Downward slope of your ear canal. Your ear canal slopes down slightly from your middle ear to your outer ear, helping water drain out.

How the infection occurs

If you have swimmer's ear, your natural defenses have been overwhelmed. Conditions that can weaken your ear's defenses and promote bacterial growth include:

  • Excess moisture in your ear. Heavy perspiration, prolonged humid weather or water that remains in your ear after swimming can create a favorable environment for bacteria.
  • Scratches or abrasions in your ear canal. Cleaning your ear with a cotton swab or hairpin, scratching inside your ear with a finger, or wearing headphones or hearing aids can cause small breaks in the skin that allow bacteria to grow.
  • Sensitivity reactions. Hair products or jewelry can cause allergies and skin conditions that promote infection.

Risk factors

Factors that may increase your risk of swimmer's ear include:

  • Swimming
  • Swimming in water with elevated bacteria levels, such as a lake rather than a well-maintained pool
  • A narrow ear canal — for example, in a child — that can more easily trap water
  • Aggressive cleaning of the ear canal with cotton swabs or other objects
  • Use of certain devices, such as headphones or a hearing aid
  • Skin allergies or irritation from jewelry, hair spray or hair dyes

Complications

Swimmer's ear usually isn't serious if treated promptly, but complications can occur.

  • Temporary hearing loss. You may experience muffled hearing that usually gets better after the infection clears up.
  • Long-term infection (chronic otitis externa). An outer ear infection is usually considered chronic if signs and symptoms persist for more than three months. Chronic infections are more common if there are conditions that make treatment difficult, such as a rare strain of bacteria, an allergic skin reaction, an allergic reaction to antibiotic eardrops, or a combination of a bacterial and fungal infection.
  • Deep tissue infection (cellulitis). Rarely, swimmer's ear may result in the spread of infection into deep layers and connective tissues of the skin.
  • Bone and cartilage damage (necrotizing otitis externa). An outer ear infection that spreads can cause inflammation and damage to the skin and cartilage of the outer ear and bones of the lower part of the skull, causing increasingly severe pain. Older adults, people with diabetes or people with weakened immune systems are at increased risk of this complication. Necrotizing otitis externa is also known as malignant otitis externa, but it's not a cancer.
  • More widespread infection. If swimmer's ear develops into necrotizing otitis externa, the infection may spread and affect other parts of your body, such as the brain or nearby nerves. This rare complication can be life-threatening.

Prevention

Follow these tips to avoid swimmer's ear:

  • Keep your ears dry. Dry your ears thoroughly after exposure to moisture from swimming or bathing. Dry only your outer ear, wiping it slowly and gently with a soft towel or cloth. Tip your head to the side to help water drain from your ear canal. You can dry your ears with a blow dryer if you put it on the lowest setting and hold it at least a foot (about 0.3 meters) away from the ear.
  • At-home preventive treatment. If you know you don't have a punctured eardrum, you can use homemade preventive eardrops before and after swimming. A mixture of 1 part white vinegar to 1 part rubbing alcohol may help promote drying and prevent the growth of bacteria and fungi that can cause swimmer's ear. Pour 1 teaspoon (about 5 milliliters) of the solution into each ear and let it drain back out. Similar over-the-counter solutions may be available at your drugstore.
  • Swim wisely. Watch for signs alerting swimmers to high bacterial counts and don't swim on those days.
  • Avoid putting foreign objects in your ear. Never attempt to scratch an itch or dig out earwax with items such as a cotton swab, paper clip or hairpin. Using these items can pack material deeper into your ear canal, irritate the thin skin inside your ear or break the skin.
  • Protect your ears from irritants. Put cotton balls in your ears while applying products such as hair sprays and hair dyes.
  • Use caution after an ear infection or surgery. If you've recently had an ear infection or ear surgery, talk to your doctor before you go swimming.