Swimmer's itch is a dermatities that develops on parts of the
body that have been exposed to lake water containing certain
larval forms of flatworms. Reddened spots, called papules, form
on the body within hours after exposure
itch intensely for several days before subsiding. After approximately
one week, the symptoms usually disappear. In severe cases, a
person can develop a fever, become nauseated and spend several
sleepless nights suffering from intense itching.