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Wisconsin Department of Health Services

Communicable  Diseases Subjects A-Z



Sexually Transmitted Diseases


Disease Reporting

Swimmer's itch

(cercarial dermatitis, shistosome dermatitis)

Swimmer's itch is a skin rash caused by a parasite (shistosomes) which ordinarily infect birds, semi-aquatic mammals, and snails. Common grackles, red-winged blackbirds, ducks, geese, swans, muskrats, and moles have been found to carry the parasite. As part of their developmental life-cycle, these parasites are released from infected snails, migrate through the water, and are capable of penetrating human skin. After penetration, these parasites remain in the skin and die, but can cause an allergic reaction in some people. The parasite does not mature, reproduce, or cause any permanent infection in humans.

General information

Swimmer's itch fact sheet - Hmong - Spanish


Wisconsin Local Health Departments - Regional offices - Tribal agencies

Last Revised: March 04, 2014