What is Swimmer’s Itch?

homeboardsSwimmer’s itch is a rash caused by certain parasites that normally live in freshwater snails and on certain waterfowl.  I won’t go into the particulars of this parasite’s lifecycle but if you’re curious it involves snail intestines and duck poop.  If you’d really like to know all of the gory details, Hope College’s biology department has an excellent and very thorough website where you can find more information.  http://www.swimmersitch.org

These parasites tend to live in warm shallow water and if you go swimming where the parasites are present, they can burrow into your skin.  However, humans are not suitable hosts so the parasite dies while still in your skin.  This is what causes the itching and the rash.  Anyone who has ever spent time in the southern United States knows exactly what this is like as “chiggers” do the same thing.  They burrow in the skin and die causing an allergic reaction.

The good news is that swimmer’s itch typically clears up on its own within a few days. In the meantime, you can control itching with over-the-counter medications like topical antihistamines or calamine lotion.  Occasionally a severe case warrants a visit to the doctor and prescription medication.

While swimmer’s itch is not entirely preventable, there are some precautions you can take to keep these nasty little parasites from invading.

  1. Don’t spend a lot of time in shallow water.
  2. Avoid swimming in areas where there is an onshore wind.
  3. Towel off immediately after leaving the water then rinse off and remove your bathing suit.
  4. Sure they’re cute, but don’t feed the ducks.
  5. Keep riprap off your beach. Riprap is effective in preventing erosion, but it also provides an excellent surface for snails to attach their eggs.  A large snail population increases the chances of swimmer’s itch.

If you do find you have swimmer’s itch on your beach, be a good neighbor and post a sign warning other swimmers.

Often a lake association will address the problem of swimmer’s itch.  For at least 50 years, copper sulfate has been used to reduce the snail population; breaking the parasite life cycle. The use of copper sulfate is regulated so be sure to check with the State and the appropriate county and city officials for regulations and licensing. There is also a drug that can be used on the water fowl that play host to the adult worm.

However, because the parasite’s life cycle is complicated and it’s difficult to treat all of the snails and all of the infected water fowl, there is no way to completely eradicate swimmer’s itch.

Here’s to an itch-free summer at the lake.  If you have been to a beach that’s been infected with swimmer’s itch, please let us know via the comments page.  Our primary goal is to keep our readers well informed.

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