Cercarial dermatitis, also known as “swimmer’s itch,” is an uncomfortable rash caused by microscopic parasites found in freshwater lakes. As we enter the swim season, it is important to be aware of how to avoid this pesky parasite.
Prevention is key! You can greatly reduce or even prevent swimmer’s itch by using a few simple precautions together throughout the swim season.
- Use Protective Clothing: Wear waders when installing boat docks, etc. Full-body swimsuits and tight-fitting rash guards can prevent the parasite from reaching your skin.
- Dry Immediately: Vigorously rub your skin with a dry towel, especially behind the knees, underarms, and around swimwear edges.
- Swim Later in the Day: Risk is highest in the morning; opt for afternoon or evening swims.
- Avoid Swimming in Onshore Winds: Wind blowing from the lake toward shore can push parasites into shallow water.
- Swim in Deeper Water: Parasites are more concentrated in warm, shallow areas near shore.
- Create a Barrier with Eco-Friendly Sunscreen: Applying mineral-based, waterproof sunscreen may prevent parasites from penetrating the skin.
If you get swimmer’s itch, use over-the-counter antihistamines and anti-itch creams to help relieve discomfort. Most cases clear up on their own and don’t need medical attention, but if the rash is severe, contact a doctor. The Glen Lake Association works with a variety of partners to better predict and understand swimmer’s itch. If you get it, please report your case online.