A website from the University of Alberta is tracking and mapping cases of swimmer’s itch across North America.

Swimmersitch.ca is a project from the U of A’s School of Public Health, led by researcher Patrick Hanington. It launched in 2012.

The website collects reports of the rash from “citizen scientists” and uses the data to pinpoint the lakes where swimmer’s itch is most prevalent, in Alberta and across North America.

Swimmers can’t avoid the itch entirely, but the researchers hope the website will help people decide where and when to swim.

"Part of it is now reporting when people are getting itch in sort of more real time so people can make informed decisions about where to go swimming based on where other people have reported on getting swimmer’s itch recently," Hanington told CTV News Edmonton. "We also know that July and early August tend to be when we see swimmer’s itch most frequently."

Swimmers itch is a rash developed after swimming in contaminated water, an allergic reaction to microscopic parasites that infect birds and mammals.

Symptoms can appear within minutes or days of can include:

  • Tingling skin
  • Burning skin
  • Itchy skin
  • Small reddish pimples
  • Small blisters

Swimmer’s itch doesn’t require medical attention unless it becomes infected. The most important advice is to avoid scratching.