Circarial dermatitis, or “swimmer’s itch” has been reported at Lake Crescent in Olympic National Park.
Swimmer’s itch is an allergic reaction to a small aquatic parasite that normally infects snails, as well as certain aquatic birds and mammals. Though it does not survive in humans, it causes intense itching and a rash, which appear within several hours to several days. The rash can last for up to a week though scratching can prolong the symptoms.
Swimmer’s itch has been reported frequently in the past at Lake Crescent and is found widely throughout the United States. It occurs naturally in lakes and ponds and is not an indicator of pollution.
“The best prevention of course, is to avoid swimming in affected areas,” said Superintendent Bill Laitner. “However, if people choose to swim in Lake Crescent, there are simple steps that can lessen the risk of developing swimmer’s itch.”
The most important prevention is to immediately remove all water from the skin by rubbing with a towel or showering; water should not be allowed to evaporate on the skin. Care should be taken to dry all skin areas, including underneath swim suits.
If swimmer’s itch does develop, over the counter remedies such as hydrocortisone cream, anti-itch lotions or baking soda or colloidal oatmeal baths may offer some relief.
Last updated: February 28, 2015