Swimmer's itch rash from Michigan bodies of water: Treatment, prevention information

Hot temperatures might have you itching to go for a cool dip in one of Michigan’s many lakes — but the dip itself might leave you itching.

At any point in time, several Michigan beaches and bodies of water may be closed due to high bacteria levels and contamination. These bacteria and other microscopic parasites can cause irritating skin conditions. Swimmer's itch, otherwise known as cercarial dermatitis, is one such condition that can affect humans.

According to the Center for Disease Control, swimmer’s itch arises from a water-borne parasite that originates from the feces of water fowl, such as ducks, and inhabits snails. The problem arises when the parasite leaves its first host (a water snail) and instead of finding a fish or bird — its next host, typically — to attach to, finds the flesh of an unsuspecting swimmer or lake frolicker. The parasite burrows under the skin and dies quickly, but a rash can develop minutes, hours or even days after coming into contact with contaminated water.

Swimmer’s itch is rare, but cases rise during the summer months in areas around freshwater and saltwater lakes. Crystal Lake in North Michigan’s Benzie County, for instance, reported a 1,000% rise in cases of swimmer’s itch in August, compared to the same time in 2022.

So, before you cannonball into a lake this summer, read on about swimmer’s itch, how one contracts it, how to treat it, and how to prevent it.

What causes swimmer’s itch?

Swimmer’s itch can be contracted if you come in contact with contaminated water, say by swimming or spending time in a contaminated freshwater or saltwater lake or public pool. The parasite burrows into the skin of the swimmer and the immune system reacts, causing a rash.

It's important to note that swimmer's itch is not contagious. The parasite does not survive under human skin.

What are the symptoms of swimmer’s itch?

Small red pimples and blisters accompanied by itching, burning and tingling of the skin near the rash are the most common symptoms. They can last up to a week, per the CDC.

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What are swimmer’s itch treatments?

Per the CDC, most swimmer’s itch cases do not need medical attention. Corticosteroid creams and cold compresses can provide relief, as well soaking with Epsom salts or drawing up an oatmeal bath. A baking soda paste (baking soda mixed with water) can also help.

Last but not least, shun the response that is most gratifying in the moment: scratching. We all know not to do it, and yet, scratching will increase the chances of infecting the rash further.

If the itch is unbearable, pharmacists can provide prescription-strength anti-itch lotions or antihistamines.

How do you prevent swimmer’s itch?

The most straightforward way to avoid swimmer’s itch is to avoid wading into contaminated waters. If you’re in Michigan, you can check which lakes are closed because of contamination on the website of the Michigan Department of Environment, Great Lakes and Energy. Barring that, swimming in deeper waters is less risky, since larvae are commonly found in shallow or weedy waters by the shoreline. Run (well, swim away quickly) if you spot a lot of snail shells or muddy, mucky waters.

According to the Crystal Lake and Watershed Association, early morning poses the greatest risk of coming into contact with larvae.

Swimmer’s itch guards do exist in the form of gels specially formulated to repel waterborne parasites. Apply waterproof sunscreen and insect repellent as a barrier, and towel off and shower after leaving the water.

What if my dog gets swimmer’s itch?

If your dog is like a fish in water in the summertime, you might want to find ways to protect your dog from the water’s microscopic parasites. Many of the same rules apply: Avoid visiting contaminated water bodies and steer away from the shores or weeds. Dry off your dog with a clean, dry towel after a dip in the water. If you notice an itch or scratch, you might want to consult your vet for treatment options, like an anti-itch cream or shampoo, to speed up the healing process.

This article originally appeared on Detroit Free Press: Swimmer's itch rash in Michigan: Symptoms, treatment, more