Swimmers Itch

Any instances of Swimmer’s Itch, please report the information via our form –  Report Swimmer’s Itch Online
It is important to track this information.

Female Common Merganser

Female Common Merganser

How is it transmitted?

Swimmer’s itch starts out as an egg on intestinal lining of waterfowl, mostly ducks. Eggs are released into the water and hatch into “miricidia” that enter snails. Snails then release “cercaria” that swim in search of waterfowl, to complete the cycle. The cercaria causes swimmer’s itch in humans by burrowing into the skin where they quickly die. The cercaria typically inhabits shallow water which facilitates coming into contact with a duck (its definitive host. Once it’s in the duck, it easily moves around the lake, and ultimately along the shores.

The Common Merganser

(Mergus merganser) Mergansers are the primary transmitters and spreaders of Swimmer’s Itch. They are large bodied ducks that live on freshwater rivers and lakes and nest in tree cavities, often within 1/4 mile of the water.

Male Common Merganser

Male Common Merganser

What Is Being Done?

Gerrish, Lyon Townships and the Michigan Department of Natural Resources with support from the Higgins Lake Foundation and Higgins Lake Property Owners Association are working to find solutions. Gerrish and Lyon Townships established a Swimmer’s Itch Task Force in 2013 to gather and share information, consider options and implement measures to mitigate the impact of Swimmer’s Itch. This spring an “Avoidance Program” will be implemented to scare these ducks off the lake and discourage nesting. Gerrish Township this spring contracted with Northpoint Fisheries Management to implement a plan to eliminate and Harass Common Merganser ducks. The $28,000.00 plan was funded by Gerrish Township and the Higgins Lake Foundation. The plan was started in early spring and concluded on May 22nd. That action is deemed  to be a success although there is still research taking place by Dr. M. Luttenton PHD as well as follow up by Mr. Steve Sendek. Donations to help fund swimmers itch programs can be sent to the following addresses below.

View Northpoint Final Report  



Not all waterfowl transmit Swimmer’s Itch. It is occasionally found in Mallards but is not carried by these other waterfowl that use Higgins Lake.

Mallard (Anas platyrhynchos) mallard
Hooded Merganser (Lophodytes cucullatus) hooded-merganser
Wood Duck (Aix sponsa) wood
Common Loon (Gavia immer) common-loon

What is Swimmer’s Itch?

Female Common Merganser

Female Common Merganser

Swimmer’s Itch, also called cercarial dermatitis, is an irritation of the skin caused by the larvae of certain parasites (Family Schistosomidae) that affect aquatic life and waterfowl. They do not parasitize humans, but do burrow into human skin trying to complete their life cycle. The larvae die shortly after enter the skin causing an allergic reaction that is “the itch”. Swimmer’s Itch is fairly common in many of the pristine lakes in our area of Northern Michigan. It also occurs in at least 30 other states as well as Canada, Europe, Africa, and Asia.


Reactions to Swimmer’s Itch vary widely. Some individuals are not noticeably affected while others develop allergic reactions that can be mild to severe. Young children and people with fair skin may be more susceptible than others. Common Symptoms include: tingling, burning, or itching of the skin and small reddish bumps or blisters. Symptoms may last up to a week or more but will gradually go away.

Treatment of Swimmers Itch

Do not scratch as this can cause the rash to become more irritated or infected.

  • Use corticosteroid cream.
  • Apply cool compress to affected areas.
  • Bathe in Epsom salts or baking soda.
  • Soak in colloidal oatmeal baths.
  • Apply baking soda paste.
  • Use an anti-itch lotion.

If itching is severe a health care provider may prescribe lotions or creams to lessen symptoms.

Prevention – What Can You Do?

  • Avoid swimming in shallow water near shore where swimmer’s itch is most common.
  • Use a Swimmer’s Itch cream or waterproof sunscreen with 15 SPF or greater before entering the water.
  • Shower or towel dry rubbing vigorously after leaving the water.
  • Do not attract waterfowl to swimming areas.
  • Help educate others on the issue.
  • Volunteer to help the Avoidance Program.

Michigan State Extension Information Bulletin on Swimmers Itch: please click the below link:


Quantifying Schistosome Abundances