Exostosis develops when repeated exposure to cold water causes bone to grow abnormally in your ear. Usually, two bony swellings (exostoses) slowly appear on the lower wall of the deep part of your ear canal, often with a third, smaller lump in the upper part.
People who swim or surf a lot in cold water often get exostosis. With continued exposure to cold wind and water, exostosis will get worse. If the swellings narrow your ear canal too much, wax and water can get trapped in the ear, which can cause infection and hearing loss.
Avoiding exposure to cold water by not swimming, or by using earplugs while swimming, might prevent the swellings from growing bigger.
How is exostosis treated?
You can have surgery to remove the abnormal bone growths. Depending on the condition of your ear canal and the type of surgery you have, it might take several weeks for your ear canal to heal.