A 2004 study found that the "se of a cotton-tip applicator to clean the ear seems to be the leading cause of otitis externa in children and should be avoided." Instead, wiping wax away from the ear after a shower almost completely cleans the outer one-third of the ear canal, where earwax is made. In the US between 1990 and 2010, an estimated 263,338 children went to hospital emergency rooms for cotton swab injuries, accounting for an estimated annual hospitalization of 13,167 children.