Swimmer’s Itch Outbreak Plagues Wisconsin Lakes in 2023
Last weekend, I sent my grandbabies on a mission to catch some crayfish for my office aquarium.  My youngest grandson came out of the lake and a few hours later said he was itchy.  My daughter checked him out and I concluded that he has ‘the itch’.
Swimmer’s itch, also known as cercarial dermatitis, is a common skin condition caused by an allergic reaction to certain parasites found in freshwater bodies. This summer, Wisconsin is experiencing a significant outbreak of swimmer’s itch.

Causes and Factors Contributing to the Outbreak
Swimmer’s itch is primarily caused by parasitic flatworms, known as cercariae, which are naturally found in freshwater lakes and ponds. These microscopic parasites typically infect waterfowl, such as ducks and geese, as part of their life cycle. The cercariae are released into the water through the feces of infected birds and then seek out specific hosts, including humans, for a brief period.
The outbreak of swimmer’s itch this summer can be attributed to several factors. Firstly, favorable environmental conditions, including warm water temperatures and stagnant or slow-flowing water, provided an ideal breeding ground for the parasites. Additionally, increased populations of infected waterfowl, along with heightened human activity in the lakes, contributed to the higher prevalence of swimmer’s itch cases.

Symptoms and Impact on Public Health
Swimmer’s itch manifests as a skin rash or itchiness, which usually appears within hours of exposure to the parasites. The symptoms typically include small, itchy red bumps or blisters on the skin, accompanied by a tingling or burning sensation. Although the condition is not considered a severe health threat, it can cause considerable discomfort and inconvenience to those affected.  My grandson felt better after a couple hours.
Local health departments received a surge in reports of swimmer’s itch cases, with both residents and tourists experiencing the discomfort associated with the condition.  The affected individuals often sought medical advice to alleviate symptoms and ensure proper treatment, resulting in increased strain on healthcare facilities.

Prevention and Management Strategies
Preventing swimmer’s itch requires a combination of personal precautions and environmental management. Swimmers and beachgoers are advised to avoid swimming in areas with high concentrations of waterfowl, where the risk of exposure to cercariae is greater.  There have been a few ducks at the Lake Metonga Beach every morning. Additionally, promptly drying the skin with a towel and rinsing off with fresh water after
leaving the lake can help minimize the likelihood of infection.

For more information contact Steve Kircher, County Conservationist-Land Information/GIS Director at 715-478-1387 or by e-mail at .


Conservation Corner is a weekly article produced by the Forest County Land & Water Conservation Department. For more information contact Steve Kircher, County Conservationist-Land Information/GIS Director at 715-478-1387 or by e-mail at .