(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.
itch fact sheet -
Local Health Departments - Regional offices - Tribal agencies
March 04, 2014