Swimmer’s Itch

Swimmer’s itch is a skin rash caused by an allergic reaction to microscopic parasites called schistosomes. These parasites naturally infect birds, mammals, and snails. When released into water, the parasite may encounter a swimmer and burrow into the skin. Although not associated with any disease, these parasites can cause an unpleasant itchy dermatitis.  In 2004, a newly invasive snail called the Japanese bubble snail was discovered at Robert Crown Memorial Beach in Alameda. This snail was shown to be shedding a previously unknown schistosome.

If you believe that you are experiencing swimmer’s itch symptoms, contact the Alameda County Department of Environmental Health at (510) 567-6700 to report your case. Once a case is reported and verified, warning signs are posted at the site to inform swimmers and beachcombers of the potential risk and precautions they should take.