Swimmer's Itch 101

Find out which parasites are digging into your skin.

Swimmer's Itch
Woman scratching. swimmer's itch

You know the risk factors for swimming shoulder and the symptoms of swimmer’s ear, but what do you know about Swimmer’s Itch? Swimmer’s itch is just as unpleasant as it sounds. It is not something you can get in the pool, but if you are an open-water swimmer or you like to jump into the local lake, you may be at-risk for Swimmer’s itch.

What is Swimmer’s Itch?

Swimmer’s itch is a rash that can develop after swimming in freshwater, such as lakes, ponds and lagoons. Swimmer’s itch, although not as common, can affect swimmers in salt water as well.  

The medical term for swimmer’s itch is ‘cercarial dermatitis’. What is it? Swimmer’s itch is a skin irritation that can develop after being exposed to trematode parasites of aquatic birds. Cercariae is the larval stage of parasitic flatworms. The initial hosts are snails, but the final host is aquatic birds. If you are itching, it is because the cercariae released by aquatic and land snails have mistakenly penetrated your skin instead of its host’s. When the larvae enter your skin’s top layer, the larvae die. You have an allergic reaction to the microscopic invaders when your body’s immune system attacks the invader. As a result, you experience the discomfort and pain of swimmer’s itch.

Symptoms of Swimmer’s Itch

The symptoms of swimmer’s itch are straightforward.

  • Reddish pimples or blisters
  • Itchy or tingling sensation
  • Inflammation
  • Hives (occasionally

​Swimmers who suffer from swimmer’s itch will notice a rash only on parts of the body that were exposed to the water. If you did more than wading in the water, you are going to be uncomfortable for a couple days. Symptoms can develop within 24 to 48 hours of being exposed to the parasites. If you have multiple spots on your body, it is not because the parasite is spreading throughout your body. Multiple locations mean your skin has been exposed multiple times.

Relief from Swimmer’s Itch

The good news is: humans are not suitable hosts for the larvae. The bad news is: you will suffer the discomforts for a day or two. If left untreated, you can experience symptoms for several weeks. Tackle the itch as soon as you begin to squirm. To treat swimmer’s itch, try the following methods:

  • Don’t scratch!
  • Rinse your body off in the shower and pat-towel dry. This will not rid your body of the parasites, because they have already imbedded into your skin, but a cool shower will ease your discomfort and prepare your skin for any topical solutions you may use.
  • Rinse the affected area – if a small area – with rubbing alcohol. Once the area has dried, rub calamine lotion or a hydrocortisone cream on the area.
  • To control itch and inflammation, apply a cool compress to the affected area or take a cool shower.
  • Take an oatmeal bath and follow up with an anti-itch lotion.
  • Take an Epsom salt bath or add baking soda to your bath water.
  • Make a baking soda paste (out of baking soda and water) and apply it to the affected area.

If you scratch too much, you can cause develop a skin infection. If you develop a skin infection, or you notice the rash is getting worse, contact your physician right away. Tell your doctor that the rash developed after swimming.

Can You Spread it?

Nope. Swimmer’s itch is not spread from person to person. Humans are not the primary hosts, waterfowl and other aquatic animals are. Common hosts include:

  • Swans
  • Red-winged blackbirds
  • Muskrats
  • Mice
  • Beavers
  • Geese
  • Ducks
  • Gulls.

Ways to Avoid Swimmer’s Itch

You cannot see the parasites on the water. To avoid swimmer’s itch, don’t bust out a microscope at the beach. Try these tips:

  • Stick to the pool. Pools that are well maintained and with appropriate chlorine levels are not suitable for the larvae.
  • As soon as you exit the water, towel dry. Rub the skin vigorously with a towel. It is important to towel dry little ones, too. Kids are susceptible because they are more likely to wade in the water for a long time and not dry off with a towel.
  • Avoid swimming in areas where snails are found. Marshy areas are snail hotbeds.
  • Do not feed birds near the water or swim where people feed birds.
  • Avoid areas with posted warnings.
  • If you are an open-water swimmer, wear a bodysuit.

Itchy rashes are never fun, but this guide can help you avoid it in the water and feel better sooner if you do experience to swimmer’s itch.