Bather’s itch, also called schistosome dermatitis, is the term given to a blotchy rash on the skin occurring in those bathing in water which is infested with the larvae of certain trematode worms known as schistosomes. The worm is parasitic in snails. The skin rash is caused by penetration of the skin by the free-swimming larval cercaria. Bather’s itch is common in many tropical and subtropical parts of the world.