WEB EXTRA: Avoiding Swimmer's Itch in MN Waters
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:
- Keep waterfowl away from your dock and shoreline. If you are feeding waterfowl (ducks and geese) from your dock - stop. If ducks like to rest on your dock, do what you can to discourage them. You can try putting an owl wind sock or statue on your dock and move it around occasionally so the ducks don't become accustomed to it.
- Stay out of the water by the shore. If ducks don't congregate around your dock, the swimmer's itch organism may originate somewhere else in the lake and is being brought to your shoreline by wave action or currents. You may want to try swimming from a raft or boat farther out from shore where you are less likely to come into contact with the cercaria. Of course, this strategy may not be practical if you don't swim or have young children who want to play in the water near shore.
- Dry off with a towel as soon as you get out of the water. When you get out of the lake, don't let the water evaporate off your skin. The organism in the droplets of water on your skin will look for somewhere to go as the droplet of water evaporates.
Symptoms of Swimmer's Itch:
- Tingling, burning, or itching of the skin.
- Small reddish pimples.
- Small blisters.
Ways to Relieve the Itch:
- Use corticosteroid cream.
- Apply cool compresses to the affected areas.
- Bathe in Epsom salts or baking soda.
- Soak in colloidal oatmeal baths.
- Apply baking soda paste to the rash (made by stirring water into baking soda until it reaches a paste-like consistency).
- Use an anti-itch lotion.
- Though difficult, try not to scratch. Scratching may cause the rash to become infected. If itching is severe, your health care provider may suggest prescription-strength lotions or creams to lessen your symptoms.