Swimmer's ear (otitis externa) is an inflammation and infection of the ear canal. It occurs when the protective film that covers the ear canal (lipid layer) is removed. This causes the ear canal to look red and swollen; it may be narrower than normal and is tender when the outside of the ear is gently pulled up and back.

Swimmer's ear may develop when water, sand, dirt, or other debris gets into the ear canal. Since it often occurs when excess water enters the ear canal, a common name for this inflammation is swimmer's ear. If you have had swimmer's ear in the past, you have a higher risk of having it again.

Exostoses are bony overgrowths in the ear canal. They are caused by repeated exposure to cold water and commonly occur in divers and surfers. Exostoses may not cause symptoms, or they may lead to ear infections and hearing loss, especially if they are big enough to block the ear canal.

Other causes of inflammation or infection of the ear canal include:

1.Scratching the ear canal with a cotton swab, bobby pin, fingernail, or other sharp object.
2.Cleaning the ear canal harshly or with a sharp object.
3.Use of earplugs.
4.Bubble baths, soaps, and shampoos.
5.Chronic skin conditions, such as eczema, psoriasis, or seborrhea.
6.Allergies.
7.Use of stereo headphones inserted into the ear.
8.Excessive sweating from physical activity.