How to Prevent Swimmer’s Itch in Your Pond or Lake

When it comes to summer nuisances, Swimmer’s Itch easily trumps mosquito bites. Reddened spots, called papules, can itch intensely for up to a week, even with treatment. That could easily ruin a weekend, or even an entire vacation. Once you’ve had a case, you certainly won’t want to get it again! So what is the best way to prevent Swimmer’s Itch?

Swimmer’s Itch, also called mercurial dermatitis, is caused by flatworm larvae hosted by a particular variety snails. These snails are typically is found in shallow ponds or lakes, and tend to concentrate near the shoreline where the water is warmer. The snails release the parasites into the water and if one comes into contact with a swimmer, it burrows into the skin causing an allergic reaction and rash.

Common tips for avoiding Swimmer’s Itch include applying a barrier to your skin, such as sunscreen or a lotion before swimming, but there is no evidence that such products help prevent swimmer’s itch. Showering after swimming is also often suggested, but by that time the parasite has already moved in and rinsing won’t help. The one sure way to prevent Swimmer’s Itch is to avoid swimming in areas where it is a known problem. But that’s not always possible, especially if the problem is in your own lake or pond.

The best option is get rid of the parasite. To get rid of the parasite, you need to get rid of the snails. One way to do that is to treat your shoreline with a chemical molluscicide such as Copper Sulfate. Copper Sulfate is toxic to the snails carrying the parasite but safe for swimmers. Copper Sulfate is EPA approved and people can swim during and after application. It sinks to the bottom where the snails live and then dissolves. Treatment should be effective in a few days and follow-up applications are typically required. If it sounds like a small price to pay for itch-free swimming for you and your family, it is! Now if we could only figure out those mosquitos.