Summer time is all about hanging at the beach with your friends, swimming in the lakes, and floating all day in the sun. With all this relaxing in the water, you could be getting a little more than you bargained for. Swimmers itch, an itchy rash caused by certain parasites that normally live on waterfowl and freshwater snails, could just be that extra something you take home from the beach.

On warm, sunny days, especially in calm freshwater lakes or ponds, these parasites can be released into the water. During your swim, these parasites might burrow into your skin, where they cause the swimmers itch rash. But, humans are not suitable hosts for these parasites, so the parasites soon die.

Swimmers itch is characterized by an itching that may begin in just an hour or two and last as long as two days after swimming, and a red, raised rash that also appears.

The cause of swimmers itch is an allergic reaction to parasites that migrate from snails to ducks, geese, gulls, swans, muskrats and beavers. The parasites then return to water through infected feces and eggs.

Swimmers itch is not contagious from person to person. You do not need to worry about "catching" swimmers itch from someone who has the itchy rash.

Swimmers itch usually affects only exposed skin, skin not covered by swimsuits, wet suits or waders. The rash may appear up to 48 hours after swimming in infested water, but you may also experience itching without ever developing a rash. If you are exposed to the same parasites again, the rash might become more severe.

Although uncomfortable, swimmers itch is usually short-lived. The rash of swimmers itch, also called cercarial dermatitis, typically clears up on its own within a few days. In the meantime, you can control itching with over-the-counter or prescription medications.

Your risk of swimmers itch depends on air and water temperatures that are warm enough for snails to reproduce and grow, such as in the late summer months in many parts of the world.

The return of migrating birds infected with parasites also affects the chances of contracting the parasite. The more time you spend in infested water, the higher your risk of swimmers itch. Kids have the highest risk, since they tend to play in shallow water and are less likely to dry off with a towel.

Some people are more sensitive to swimmers itch than others are. And, your sensitivity can increase each time you are exposed to the parasites that cause swimmers itch.

There really is not a prevention of swimmers itch. Just preventative measures such are discouraging duck activity, showering after swimming, and avoiding shallow waters.