Allergic reaction caused by parasites draws renewed attention to a rash called ‘swimmer’s itch’

(Update: Adding video, comments from environmental health specialist)

BEND, Ore. (KTVZ) -- There's quite a lot of water activities in Central Oregon, and that can come with a lot of warnings, including one about something called "swimmer's itch."

On Friday at Wickiup Reservoir, boaters and swimmers were out enjoying the water. But some recent visitors have reported to Deschutes County their pets appearing itchy after some time in the water.   

"It has to do with the life cycle that lives part of the time in a snail," Deschutes County Public Health Specialist John Mason said Friday. "The snail sheds it, then it starts looking for a warm-water host to transport it around."

In the search for such a host, the parasitic worm can attach to an animal, bird  or human, causing what's commonly referred to as "swimmer's itch," a rash that can occur after time in lakes or ponds.

"It will burrow into your skin, and that causes kind of an allergic reaction," Mason said. "So you can't get sick by it, but this is going to be annoying -- kind of like a mosquito bite." 

The symptoms from swimmer's itch include a small red rash on the skin -- and, of course, itching.

Mason added, "One of the ways you can cut down is rinse off your legs. Rinse off the areas that's been in the shallows, use clean water and towel off very vigorously with a towel, and that friction will break off those that haven't gotten all the way into your leg." 

He said you can treat swimmer's itch with calamine lotion or Benadryl. It tends to affect children more than adults -- because kids play in the shallow water, where the organisms tend to live. 

It most likely will go away within a week, and in most cases it won't require medical attention.

For more information on what's also called cercarial dermatitis, visit this FDA website.