Swimmer's itch caused by parasites that penetrate the skin
Feeling a little itchy after that nice swim you took in yesterday's heat?
It's an allergic reaction to a parasite that thrives in warm, freshwater lakes and rivers.
The parasite comes from snails and usually attacks birds and other small mammals.
But it also tries to get at humans, said Jon Groulx with the Sudbury and District Health Unit.
"In humans it dies within minutes [of being] embedded in the skin, and then we just develop that allergic response to it."
The resulting red, itchy rash usually goes away within a week.
There are some things you can do to prevent swimmer's itch.
Groulx noted there's increased risk to those swimming in shallow, marshy waters, and where snails are known to inhabit. Swimming an area where birds are fed also increases risk.
Some people will show no symptoms while others can have strong reactions, he added.