• Swimmer’s Itch

    (Cercarial Dermatitis; Duck Fleas; Duck Itch; Duckworms; Sea Lice; Clam Digger's Itch)


    Swimmer’s itch is a skin rash that appears after you have been swimming or wading in natural bodies of water. It is more common in warm freshwater (lakes and ponds), but it can also occur in salt water.


    Swimmer’s itch is an allergic reaction to a specific parasite. The parasite enters the water through the waste of infected birds and snails. If the parasite comes in contact with your skin, it can burrow under the skin and cause a reaction.

    Risk Factors

    Swimmer’s itch is more common after:
    • Swimming or wading in warm fresh or salt water
    • Swimming or wading in warm shallow water near the shoreline
    • Long periods of time in the water
    • Previous episodes of swimmer’s itch
    • Swimming in locations with onshore winds
    • Swimming in areas with a lot of birds
    Swimmer’s itch is also more common in children since they tend to stay in shallow water.


    Symptoms can occur quickly. In most cases, you will notice skin irritation before the rash appears. Symptoms can include:
    • Itching
    • A sensation of burning or tingling
    • Small red bumps, blisters, or pimples
    Blistering Skin from Swimmer's Itch
    Copyright © Nucleus Medical Media, Inc.


    There is no skin or blood test to diagnose swimmer’s itch. The doctor will base the diagnosis on information about recent activities and the appearance of the rash.


    The rash will go away on its own within a few days without medical treatment.
    Scratching can cause further damage to the skin and increase the risk of infection. Itching may be relieved with:
    • Soothing baths and cool compresses
    • Over-the-counter cortisone creams and anti-itch medications
    • Oral antihistamines—for more severe itching
    A severe rash may require prescription strength medication.


    To help reduce your chance of getting swimmer’s itch:
    • Apply a barrier lotion with broad-spectrum sunscreen product before going in the water.
    • Avoid swimming or wading in known contaminated waters. Also try and avoid areas of water with a lot of birds or marshy areas where there are snails.
    • Rub your (and your child’s) skin with a towel after coming out of the water.


    American Academy of Dermatology http://www.aad.org

    Centers for Disease Control and Prevention http://www.cdc.gov


    Canadian Dermatology Association http://www.dermatology.ca

    Public Health Agency of Canada http://www.phac-aspc.gc.ca


    Parasites—Cercarial dermatitis (known as swimmer’s itch). Centers for Disease Control and Prevention website. Available at: http://www.cdc.gov/parasites/swimmersitch/index.html. Updated January 10, 2012. Accessed July 29, 2014.

    Schistosomiasis. EBSCO DynaMed Plus website. Available at: http://www.dynamed.com/topics/dmp~AN~T901358/Schistosomiasis. Updated January 29, 2016. Accessed October 3, 2016.

    Swimmer’s itch. American Osteopathic College of Dermatology website. Available at: http://www.aocd.org/?page=SwimmersItch. Accessed July 29, 2014.

    Swimmer’s itch. DermNet NZ website. Available at: http://www.dermnetnz.org/arthropods/swimmers-itch.html. Updated December 29, 2013. Accessed July 29, 2014.

    Verbrugge LM, Rainey JJ, et al. Prospective study of swimmer’s itch incidence and severity. J Parasitol. 2004;90(4):697-704.

    Revision Information

  • LiveWell personal health survey

    How healthy are you really? Find out – free.Learn more

    It's time to stop guessing. If you want to make some changes but just aren't sure how, the free personal health survey from LiveWell is a great place to start.

  • HeartSHAPE Spotlight

    At risk for a heart attack? Learn more

    Fight heart disease and prevent heart attacks. HeartSHAPE® is a painless, non-invasive test that checks pictures of your heart for early-stage coronary disease.

  • Calories and Energy Needs

    Calorie NeedsLearn more

    How many calories do you need to eat each day to maintain your weight and fuel your physical activity? Enter a few of your stats into this calculator to find out.

  • Ideal Body Weight

    Ideal Body WeightLearn more

    Using body mass index as a reference, this calculator determines your ideal body weight range. All you need to do is enter your height.

  • Body Mass Index

    Body Mass IndexLearn more

    This tool considers your height and weight to assess your weight status.

  • Can we help answer your questions?

    Wellmont Nurse Connection is your resource for valuable health information any time, 24 hours a day, seven days a week. Speak to a Nurse any time, day or night, at (423) 723-6877 or toll-free at 1-877-230-NURSE.