If you head to the water over the summer, you may encounter swimmer’s itch
Avoid swimmer’s itch this summer by observing where you are swimming and rinsing off after a swim.
The summer season is in full swing in Michigan and many people take to ponds, inland lakes, and the Great Lakes to escape the heat. At times, soon after a swim, some swimmers can come down with a skin irritation that causes extreme itching. This is usually caused by what is called swimmers itch.
Swimmers itch is caused by a flatworm parasite that uses freshwater snails and waterfowl as its hosts in its life cycle. At the life stages when the flatworm parasite leaves the freshwater snail and swims freely in the water, they usually encounter waterfowl to complete their life cycle. It is when these free-swimming parasites encounter a swimmer, which can lead to swimmers itch as it penetrates the skin. These parasites die immediately upon human contact as humans are not a host for this parasite. When the parasite is in the skin, it causes an inflammatory reaction that leads to itching. It usually clears up on its own in several days.
Swimmers itch usually occurs when the air and water temperatures are warm enough for snails to reproduce and grow. This usually occurs in the late summer months. Areas that contain the swimmers itch parasite are usually along the shoreline and shallow areas where waterfowl frequent. The more time a swimmer spends in this type of environment, the risk increases for getting swimming itch.
Measures can be taken to prevent getting swimmers itch. Michigan State University Extension and Michigan Sea Grant recommend that swimmers avoid areas that are known to cause swimmers itch. These areas can include lake bottoms with organic materials that promote snail growth, such as marshy areas. Strong swimmers may consider swimming swim deeper water where they are less likely to encounter the parasite. Once leaving the water, swimmers should immediately rinse with freshwater and dry their skin with a towel. Although many people like to watch wildlife, don’t encourage waterfowl to use swimming areas frequented by people feeding them.