This is Public Health

Swimmer's itch in Alberta's lakes

Have you ever had itchy red spots on your legs after wading in a lake during the summer? Maybe you’ve noticed red rash covering the legs of children and other beach goers.

This rash, called swimmer’s itch, is a common condition caused by an allergic reaction to parasites that live in the water. Swimmer’s itch occurs in both fresh and salt waters around the world and Alberta is no exception.

Since May 2015, thirty of Alberta’s lakes have had reports of swimmer’s itch, including Pigeon Lake, Sylvan Lake, Wabamun Lake, Lake Bonavista, Lac St. Anne and Buck Lake.

Ten Things You Need to Know About Swimmer's Itch

  1. Swimmer’s itch is also called lake itch, duck rash and cercarial dermatitis (in some circles).
  2. Every lake in Alberta is likely to have the right conditions to be a home to the parasites that cause swimmer’s itch.
  3. The rash can look like small mosquito bites, pimples or blisters on the skin.
  4. Summer is the most common time to develop swimmer’s itch.
  5. Children are most often affected by swimmer’s itch because they tend to swim, wade, and play in the shallow water where the parasites live.
  6. Swimmer’s itch is not contagious and cannot be spread from one person to another.
  7. Swimmer’s itch is not dangerous and will usually go away within a week or two, although scratching can cause secondary bacterial infections.
  8. To help prevent swimmer’s itch, towel off immediately after leaving the water and avoid swimming in shallow or highly-vegetated areas.
  9. The symptoms of swimmer’s itch can be alleviated by using any anti-itch treatment.
  10. You can see if swimmer’s itch has been reported in your August long weekend destination by checking out this interactive map.

This information is based on research by Patrick Hanington, assistant professor with the School of Public Health. Hanington has studied parasitic immunology and swimmer’s itch both in Alberta and around the world since 2008.

Locally, Hanington has a number of projects underway in his lab. He and his students are working on monitoring parasite infections in Albertan lakes. Working with various provincial and municipal partners, the lab is examining what areas are affected and developing strategies for reducing transmission and improving usage of Alberta’s recreational water sites.