Friday, April 18, 2008
Helminth Infection of the Skin
Swimmer's itch is Cercarial Dermatitis. It results when bird (usually ducks, geese) schistosome eggs hatch and the resulting larvae infect a particular type of snail. Cercaria, from infected snails, are released into the water waiting to infect an unsuspecting duck. When the cercaria infect humans (the wrong host) a skin eruption occurs because the bird schistosome cercaria cannot develop further.
Cercarial dermatitis in a swimmer.
Another type of helminth skin infection that can be found in the USA is cutaneous larval migrans.
Cutaneous larval migrans results when roundworms that normally infect dogs or cats infect a human instead. The roundworm cannot develop normally because it is in the wrong host. Thus it wanders around under the skin.