Swimmer's Itch

Swimmer's Itch

Public Health Fact Sheet

What is Swimmer’s Itch?
Swimmer’s Itch, also called cercarial dermatitis, is a skin rash caused by an allergic reaction to microscopic parasites.  These parasites are released from infected snails into fresh and salt water (such as lakes, ponds, and oceans).  While the parasite's preferred host is the specific bird or mammal, if the parasite comes into contact with a swimmer, it burrows into the skin causing an allergic reaction and rash.  Swimmer's Itch is found throughout the world and is more frequent during summer months.

How is Swimmer’s Itch spread?
Swimmer’s itch is spread by direct contact with water that is contaminated with the parasite.  The primary carriers and transmitters are ducks and geese.  Humans can be exposed to the larvae when wading or swimming in contaminated lakes, ponds, and streams.

How is Swimmer's Itch treated?
Most cases of Swimmer's Itch do not require medical attention.  If you have a rash, you may try the following for relief:
  • Use corticosteroid cream
  • Apply cool compresses to the affected areas
  • Bathe in Epsom salts of baking soda
  • Soak in colloidal oatmeal baths
  • Apply baking soda paste to the rash (made by stirring water into baking soda until it reaches a paste-like consistency)
  • Use an anti-itch lotion
Though difficult, try not to scratch.  Scratching may cause the rash to become infected.  If itching is severe, your health care provider may suggest prescription-strength lotions or creams to lessen your symptoms.

How can Swimmer’s Itch be prevented?

Shower as soon as possible after swimming.  Towel off briskly to help remove the larvae which causes the itch.  Avoid swimming in areas at higher risk (i.e. where snails are more commonly found) like marshy areas.

Additional information is available on the CDC website at www.cdc.gov/parasites/swimmersitch/

Symptoms of Swimmer's Itch

  • A dull prickly sensation as the larvae burrow into the skin
  • Small red spots on the skin which begin to itch and cause a rash
  • Severity of the rash can vary from person to person

February 2020