Tiny flatworms like to find birds and small mammals as hosts. The eggs of the parasite enter the water through the animal’s feces.
When they hatch, they grow in a type of snail that lives in shallow water until it’s time to find a new host.
Sometimes they’ll mistake humans for animals and try to burrow in.
“They're not able to survive in human skin, so they'll die, and this is kind of what causes that itchy reaction,” said Vilas County Public Health Department Community Health Educator Caroline Thompson.
Swimmer’s Itch typically looks like small red bumps or blisters on the skin.
It can be itchy and uncomfortable, but Thompson stresses it’s not dangerous.
You can prevent it by avoiding swimming in shallow waters, especially where you know ducks or other animals like to congregate.
Rinse and dry off as soon as possible after being in the lake and change out of your wet swimsuit.
If you do get it, itch relief creams like hydrocortisone or calamine lotion can help with the symptoms.
“I think developing any rash and then hearing parasite can sound really scary, so it's just important to remember that this kind of just comes with the territory of swimming in the lakes,” said Thompson. “Know how to prevent it, know how to treat it, and don't let it keep you from enjoying your summer and enjoying the lake.”
Cases of swimmer’s itch tend to peak around early July in northern Wisconsin.
If the rash last longer than a week, the pain worsens, or you just have questions about it, Thompson recommends reaching out to your primary care provider.
