It's the bane of a day at the beach, the unwelcome result of too much summer fun in the water.
Swimmer's itch isn't a serious infection, but don't tell that to someone whose body is covered with red, dime-sized welts. Sleeping and eating become secondary concerns. Calamine lotion, hydrocortisone cream and Benadryl help, but the itch doesn't end until the parasite that causes it dies. This usually takes a few days. More serious cases can last a week or longer and should be referred to a doctor .
This summer the incidence of swimmer's itch has been about average, said Dr. Richard Roberts, an urgent care physician at the Brainerd Medical Center. Roberts said he treated about 15 cases of swimmer's itch in the week after the Fourth of July.
"It flared up when the weather got warm," he said.
Swimmer's itch has come after dips in Gull, Cross, North Long and Pelican lakes, as well as lakes in the Whitefish Chain, said Stacy Frabel, a registered nurse at BMC.
To help prevent swimmer's itch, apply an oily lotion to your skin before you swim, then shower and towel off immediately after.
Swimmer's itch results when cercaria, a parasite, burrows into your skin. Cercaria begins its life as a microscopic organism in the blood of ducks, herons, muskrats and other lake-dwelling birds and animals. Cercarian eggs pass through the host bird's or animal's intestines and into the water with other waste, where they hatch and then burrow into snails. The snails in turn discharge the cercaria and it burrows into the skin of a bird or animal and the cycle begins again.
When cercaria burrows into human skin it dies, resulting in swimmer's itch. Children get it more often than adults because they tend to spend more time in the water.
Copper sulfate is used to treat waters where swimmer's itch is found, but its effectiveness is limited, said Terry Ebinger, an aquatic biologist with the DNR.
"Snails are moved by the wind and waves," Ebinger said, "so you can treat an area and they'll be back after a day or two. The copper sulfate's gone in four to five hours so whatever moves in after that is untreated."
Swimmer's itch occurs more often in weedy lakes because weedy lakes have more snails, Ebinger said.
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