Under normal circumstances, water can enter and exit your ear canal without a problem. When water stays in your ear canal, however, it can wash away the canal's protective coating of earwax. This can cause a wet condition in your ear canal for bacteria to grow. Bacteria cause the ear canal to become red and swollen, a condition known as swimmer’s ear or otitis externa. Water in the ear and the onset of swimmer's ear can result from several causes.
Exposure to Water
Swimming, bathing or showering more often than you normally do creates a situation in which the amount of water running in and out of your ear canal increases. This tends to thin out or wash away your ear’s defense of a water-repelling layer on the skin of the ear canal, which is called cerumen or earwax. This earwax, in addition to repelling water, is acidic, which creates an environment unfavorable for the growth of bacteria.
Humid conditions can also cause wet conditions in your ear canal, creating an environment in which bacteria may grow, especially if your layer of earwax has been thinned.
Cleaning earwax from your ear removes the protective layer from the ear canal. This condition allows any water that enters your ear to create a wet environment suitable for bacterial growth. Swimmer’s ear can also result from sticking objects such as pencils, cotton swabs and fingers into your ear canal, causing injury and potential infection to the skin in your ear canal. Swimmer’s ear may also result from conditions such as psoriasis, which can affect the skin in your ear canal. Bacterial growth accompanying swimmer's ear may also occur as a result of using hair products such as hairspray or dye.
Protection During Treatment
Physician directions should be followed when you're being treated for swimmer’s ear. According to MayoClinic.com, your ear canal should be kept as dry as possible when being treated. Avoid swimming and showering and take baths instead.