Swimmer's Itch (Cercarial or Schistosomal Dermatitis)
Swimmer’s itch is an allergic reaction to a small parasite called a blood fluke. These tiny parasites are released from infected snails into fresh and salt water such as lakes, ponds, and ocean bays. Normally, the blood flukes infect a bird or mammal by burrowing into these animals’ skin. Sometimes the blood flukes may burrow into the skin of people wading, playing, or swimming in infested shallow waters. After entering the skin of people, the flukes die, causing an allergic reaction that results in intense itching, a rash, and sometimes small blisters.