(AP) -- The first national estimates of swimmer's ear say it causes about 2.4 million trips to doctors and hospitals in a year.

The also said swimmer's ear cases amounted to about $500 million in annual - or roughly $200 per visit.

Some people get the problem repeatedly, and the CDC didn't estimate how many Americans suffer swimmer's ear each year. But according to calculations by The Associated Press based on CDC statistics, more than 2 million get it.

Swimmer's ear is an itchy, painful, outer-ear infection that can occur when bacteria in swimming water get through breaks in the skin. It's commonly treated with antibiotic ear drops.

More than half the cases were in adults. The CDC released the statistics Thursday.