I am planning a vacation at a lake? What should I know about swimmer’s itch?

Swimmer's itch is a rash caused by small worm-like parasites called schistosomes. The parasites typically are in water snails and in the blood stream of marine mammals, ducks or other birds but sometimes get onto human skin. The rash is temporary but can be very itchy. It is caused by an allergic skin reaction from parasites burrowing under the skin. A reaction usually starts 10 to 30 minutes after you have been exposed.

Larva start to burrow into the skin as soon as you leave the water and die very soon. You may feel tingling as they burrow. The skin becomes itchy and irritated with very small red spots which get bigger over the next few hours. As the spots grow, itching starts. The rash and the itching range from mild to severe. If you scratch the rash too much, you may get a bad infection and severe pain. If you think your rash is infected, you should see your doctor. The more often you are exposed, the worse the symptoms are because repeated exposure increases your sensitivity to the parasites.

The rash and itching can last two to five days, but may be as long as two weeks, before slowly improving and disappearing. The rash is not contagious and is not a serious health problem but can be very irritating.

The parasites are found in many lakes and ponds in Alberta and British Columbia, especially during warm weather. They are usually around the edges of lakes and ponds and close to the surface. If you splash and wade in the shallow water at the edge of a lake or pond you are at higher risk of getting swimmer’s itch.

You can reduce the risk of swimmer’s itch by:

• avoiding lakes and ponds where swimmer’s itch is known to be common
• decreasing the amount of time you spend in shallow water
• rub your skin vigorously with a towel right away when you get out of the water or, have a shower right away and then dry off
• do not feed or attract birds to areas where people are swimming
• watch for signs posted by local health authorities around lakes or ponds warning about swimmer’s itch

Itchiness can be relieved by avoiding scratching. Ask your doctor or pharmacist about medications or lotions that may help. Lukewarm baths with baking soda or oatmeal in the water may help reduce itching. Cool compresses may provide some relief.

For more information about swimmer’s itch, or for available programs and services, contact Health Link Alberta where nurses are available 24-7 to provide health advice and information. Call 1-866-408-LINK (5465) or 780-408-LINK (Edmonton area) or 403-943-LINK (Calgary area).