Sand Hollow State Park

Swimmer’s Itch

Swimmer’s Itch is an irritating, yet harmless rash caused by the human body’s allergic reaction to a free-swimming microscopic parasite (cercarial) found in shallow water. It is found throughout the world and is more common during summer months.

Who is at risk?
Anyone who swims or wades in infested water. However, the larvae are more likely to be in shallow water by the shoreline. Children are most often infected because they tend to play in shallow water more than adults. Less than 7% of the population is affected by Swimmer’s Itch, and of those that are, most build an antibody after one reaction and do not experience symptoms again.

How does water become infected?
The adult parasite lives in the blood of infected water loving birds. The parasite produces eggs that are then passed through the bird’s digestive system. The next part of the life cycle comes when snails eats the eggs. The eggs hatch and go through the snail’s digestive system, becoming a free-swimming parasite. The next step is to once again infect a bird and start the whole cycle over. If a person becomes infected, the parasite will be killed by the human immune system. The rash or blisters that occur are the body’s allergic reaction to the parasite. The parasites do not enter the body through the skin. Their attempt to burrow in releases a chemical that irritates the skin and causes the rash.

What are the symptoms?
• Tingling, burning or itching of the skin
• Small reddish pimples
• Small blisters
These signs or symptoms may occur in as little as minutes after swimming in the water, or may take longer. The small reddish pimple will appear within 12 hours. These pimples can then turn into small blisters. Scratching the infected area can lead to secondary infections. The itching can last a week or more, but will generally go away in about three days.

Do you need to seek medical attention?
Swimmer’s Itch is not tracked by the Health Department. It is not life threatening. Most cases of Swimmer’s Itch do not require medical attention. If you have a rash you can try the following for relief:
• Corticosteroid cream
• Cool compress to the affected area
• Bathe in Epson salts or baking soda
• Soak in colloidal oatmeal baths
• Apply baking soda paste to the rash
• Use an anti-itch lotion

Can it be spread from person to person?

What can be done to reduce the risk of Swimmer’s Itch?
To reduce the likelihood of developing Swimmer’s Itch:
• Don’t swim in areas where Swimmer’s Itch is a known problem.
• Don’t swim in marshy areas where snails are commonly found.
• Towel dry or shower immediately after leaving the water. (Any of the microscopic parasites in the droplets of water on your skin will look for somewhere to go when that water starts to evaporate. The only place to go is in your skin.)
• Swim in deeper water, away from the shore