Causes of Swimmers' Ear

Swimmers’ ear is caused most often by bacteria commonly found in water and soil. These bacteria are allowed to grow because your ear’s natural defenses, which help to keep your ear clean and healthy, have been weakened. Common causes of swimmers’ ear include:

• Excess moisture in the ear. This excess water—the result of swimming, prolonged humidity or heavy perspiration—can wash away the protective earwax in your ear and create a moist environment in which bacteria can grow.
• Swimming in polluted water.
• Scratches in the ear canal. Cleaning your ear with a cotton swab or hairpin or scratching the inside of your ear with your finger can all cause breaks in the skin that allow infection to develop.
• Allergies and skin reactions. Allergies to certain hair products or jewelry can also promote infection.