The itch, which often looks like poison ivy or other similar types of rashes, is caused by microscopic flatworms which burrow into human skin. Flatworm eggs make their way to the water via the excrement of ducks, geese and other water fowl, as well as mammals like beavers and muskrats.
Though it's only in two of Iowa's lakes, in a statement released last week, DNR said: "It is likely only a matter of time before it shows up at Storm Lake, the Iowa Great Lakes and beaches at other natural lakes."
"The welts and itching caused by the parasitic little pest can last for several days to about a week," explained DNR officials. Though a nuisance, the rash doesn't typically require quire a visit to the doctor.
Patience, plus an antihistamine with calamine lotion, is the best remedy. Though if a rash becomes infected, the care of a professional physician should be sought.
"Typically, some of the things that lake users can do to avoid the severe cases, is towel off immediately after leaving the water or shower immediately," explained DNR biologist Scott Grummer. "That will really help with any degree of rash that somebody may encounter."
Of course, swimmer's itch isn't isolated to Iowa, but can crop up in freshwater bodies around the world -- especially shallow waters with snails, which serve as an intermediary host for flatworms.