Otitis externa, also called swimmer's ear, is an infection of the outer ear canal that's usually caused by bacteria. The infection is often brought on by water that stays in the ear after swimming. This makes a moist environment that helps bacteria grow.
Symptoms of otitis externa, also called swimmer's ear, are usually mild at first. They can get worse if the infection isn't treated or spreads. Mild symptoms include itching in the ear canal, slight redness in the ear or some drainage of clear fluid with no smell.
A health care provider may prescribe ear drops and tell the person to keep the ear dry.