Parasites that cause a condition known as ‘swimmer's itch’ have turned up at two lakes in Iowa, and state officials say they’ll probably spread to other lakes and beaches.
“Complaints about swimmer’s itch are starting to come in from Crystal Lake and Black Hawk Lake, and 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,” said a statement from the Iowa Department of Natural Resources.
Swimmer's itch is caused by microscopic flatworms that burrow into human skin, causing an allergic reaction that results in a rash and itching. The flatworm eggs are transferred to water by droppings from birds, including ducks and geese, and animals such as beavers and muskrats. The flatworms live in snails but will also burrow into humans.
“The welts and itching caused by the parasitic little pest can last for several days to about a week and usually don't require a visit to the doctor. An antihistamine along with calamine lotion can be used to treat the affected areas,” said a statement from the Iowa Department of Natural Resources.
The Mayo Clinic reports the rash usually affects skin not covered by swimsuits, wet suits or waders. The rash typically clears up, without treatment, within a few days. Swimmer's itch is not contagious from person to person.
The rash is sometimes misdiagnosed because it can look like poison ivy or other skin problems.
You can reduce your risk of swimmer's itch by reducing the amount of time you spend in the water, especially in shallow areas, and by drying off quickly when getting out of the lake.
It is also best to avoid swimming in marshy areas which often contain snails, which are intermediate hosts to the parasites that cause swimmers itch.
“Swimmer's itch is found throughout the world and is more frequent during summer months,” according to the Centers for Disease Control and Prevention.
If you get a rash after swimming, and it lasts more than a week or if it appears to be infected, you should consult a doctor.