WEB EXTRA: Avoiding Swimmer's Itch in MN Waters

Updated: 07/17/2013 1:23 PM KSTP.com By: Maricella Miranda

Photo: MGN Online
Photo: MGN Online

Minnesotans across the state are dipping into lakes to cool off during this week's hot temps. But in some lakes, swimmer's itch can dampen the fun.

The following is information from the Minnesota Department of Natural Resources and Centers for Disease Control and Prevention about swimmer's itch:

What's Swimmer's Itch?

It's a skin rash caused by an allergic reaction to microscopic parasites that are carried by waterfowl, semi-aquatic mammals, and snails. As a part of their life cycle, these parasites are released by infected snails into the water. This is where they may come in contact with people and burrow into skin.

A person's immune system detects it as a foreign protein, then attacks and kills it shortly after it penetrates your skin. The itching and welts are not caused by the organism living under the skin, but by an allergic reaction.

Not everyone is sensitive to swimmer's itch. Some people show no symptoms of swimmer's itch even though others swimming at the same time break out severely. Sensitivity to swimmer's itch will increase with each exposure. There are several over the counter remedies your pharmacist can recommend to help relieve the discomfort, but see your physician for a definitive diagnosis.

Where Does it Come From?

The organism that causes swimmer's itch has a complicated life history. It starts out in the intestinal lining of waterfowl, mostly ducks. The life stage that causes swimmer's itch is called a "cercaria," which is an immature stage of a blood fluke common in waterfowl.

The cercaria only lives for a day or so and typically inhabits the upper few inches of lake water. This increases its chances of coming into contact with a duck (its definitive host). Once it's in the duck, it easily moves around the lake, and ultimately along the shoreline.
Swimmer's itch is not spread from person to person.

Tips to Avoid Swimmer's Itch:

Symptoms of Swimmer's Itch:

Ways to Relieve the Itch: