Scientists look for cause of swimmer’s itch in lakes

Marjorie Mathison Hance's five grandchildren love spending time in the water at her place on Pelican Lake in Otter Tail County.

But she said one summer day in 2020, they emerged from the water, their skin blistering with hundreds of itchy, red welts. It took six weeks for one of the children’s sores to clear up.

"They were crying and really agitated, because it's a very painful and very aggressively itchy swimmer's itch,” Hance said. Her grandchildren no longer want to go in the water, she said.

When Hance talked to other Pelican Lake residents, they reported similar experiences. Swimmer’s itch had a profound impact on people's ability to enjoy the lake, she said.

"Kids are scared of it. Adults are scared of it,” she said. “It's really had a very dramatic effect."

Swimmer's itch is ca