Frequently Asked Questions:
Swimmer's itch is common around Minnesota's lakes in midsummer. Red, itchy welts appear on your skin within several hours of leaving the water. It may last a few days to several weeks, depending on your sensitivity.
Swimmer's itch comes from a microscopic parasite (Schisosome cercariae) that has a complex life cycle involving water birds or mammals, snails, and free-swimming stages. During one of its free-swimming stages, humans can be exposed to the parasites in lake water. When a swimmer leaves the water and water drops begin to evaporate, the tiny parasites burrow into the skin to try to survive. Where water is held near the skin (at waistbands and leg openings) the parasites have more time to burrow in.