As students cool down in the American River while summer winds down, they may unknowingly become part of the life cycle of a fluke, a microscopic water- bound parasite that will dig under any skin floating by, often producing an itchy rash.

Commonly known as “swimmer’s itch,” cercarial dermatitis is an allergic skin reaction to a parasite of the genus schistosomes.

Disgusting at best, the parasite begins its life in the bodies of aquatic snails and burrows into the bloodstreams of waterfowl. The birds deposit their waste in a body of water releasing the schistosomes eggs and the cycle repeats, producing contaminated water.

The most commonly affected areas is the still, shallow water along shorelines of natural streams and rivers, where bird and snail populations cohabitate.

One Sac State student, who wishes to remain nameless, experienced swimmers rash after snorkeling in the liquid brew of microorganisms that makes up the American River.

“I didn’t know what it was. I thought it was poison oak I got from swimming too close to the shore,” said the anonymous student. “It was really more annoying than anything else. It didn’t hurt, it was just a really bad itch all over. Then it faded away like a case of poison oak.”

The fluke burrows under the skin of unsuspecting swimmers who soak in the infested water leading to the itch. According to the Centers for Disease Control and Prevention, a reaction can occur immediately or up to a day after contact. Swimmer’s itch is not medically serious and will cure itself.

Symptoms include red itchy skin, swelling blisters and occasionally stuffy sinuses.

A swimmer greatly increases chances to get the rash if they allow their body to dry naturally after they leave the water. As the water evaporates off the skin it is easier for the fluke to enter the skin.

The symptoms of swimmer’s itch usually dissipate on their own, lasting anywhere from a few hours to a week. The fluke is unable to survive in the human host.

Those affected can use baking soda lotions or oatmeal baths. If the case is severe, a physician can prescribe antibiotics or stronger topical creams.

American River schistosomes are more puzzling than serious. In other parts of the world, such as the tropics of Africa and Asia, schistosomes can cause serious fatal infections as the fluke can survive in the human host.

Connie Barter, a nurse with the Communicable Disease Division of the California Health and Human Services Agency, is familiar with the local swimmer’s itch.

“(Late summer) is the time of year that it is most common,” Barter said. “By state law, swimmer’s itch is supposed to be reported.”

The Health and Human Services agency wants to be informed of cases of contaminated water even though it is not a serious issue. If there are bulk cases in an area the water can be tested and dealt with by the state.

“The problem is that people don’t go to a doctor because the symptoms go away,” Barter said. “Most people don’t know what it is.”

Late summer offers ample time for college kids to soak up sun in any of Sacramento Valley’s spectacular waterways. Kirk Grant, the manager of American River Raft Rentals in Rancho Cordova, attributes most of his business to students.

“On Labor Day weekend, probably 75 percent of our customers were students,” Grant said. “Sacramento does have great opportunities for rafters.”

The Sacramento waterways and their bacterial components are not uniquely contaminated.

Richard Sanchez, manager of the Environmental Health Division of the Department of Health and Human Services, said it is possible to get swimmer’s itch from any natural bathing place.

“Traditionally, our complaints come from areas where birds are steadily present, especially bridges.”

Sanchez added that swimmers can work to help themselves minimize exposure to bacteria in the river.

“Dry off immediately after you get out of the water,” Sanchez said, “and don’t swim where birds are. You greatly lessen your chance for swimmer’s itch.”

So enjoy the water channels Sacramento has to offer, jump in, cool down, and try to remember to dry off.

“Don’t drink the water,” Sanchez said.