By Kristi Winter, CNP, Family Medicine

Lake itch, also known as swimmer’s itch, is caused by an allergic reaction to microscopic parasites in the water that burrow into your skin while you’re swimming or wading in warm, shallow water. It’s no more dangerous than a mosquito bite, but the itch feels even itchier. However, not everyone has an allergic reaction to these organisms, so some people may not show any symptoms, while others, swimming at the same beach at the same time, may have severe breakouts. Lake itch becomes more common during the height of summer. Wind direction may cause it to be more prevalent in certain areas temporarily.

Lake Itch Symptoms

Since it appears near the shore, the legs are commonly involved, while swimsuit areas may be spared. Symptoms usually appear within 24 hours of exposure and last a few days. Symptoms can include:

• Red pimple-type rash
• Intense itchiness
• Occasional burning, tingling, or small blisters

Home Treatment for Lake Itch

Taking an oral over-the-counter antihistamine such as Benadryl, or applying anti-itch cream may be used to help decrease discomfort. Soaking the affected area with a moist, cold compress may also relieve itching. Avoid lake water swimming, wading, or other water activities in the lake until the rash has cleared. Returning to the water where the parasite is suspected could cause a more severe rash to occur.

Much like poison ivy, your sensitivity increases with each exposure. Taking precautions before and after your first encounter is always a good idea. The best way to “treat” swimmer’s itch it is to prevent it.

Reduce Your Risks

• Apply water-resistant sunscreen on all exposed skin 15 minutes prior to entering the lake and reapply as recommended.
• Vigorously dry off with a towel as soon as you get out of the water instead of letting the water evaporate off your skin. Organisms living in the water droplets will look for somewhere to go as the droplets disappear. Shower as soon as possible.
• Steer clear of areas in lakes known to have a high incidence of lake itch/swimmer’s itch.
• Don’t feed ducks or other semi-aquatic animals off your dock or swimming beach, since they are large factors in where the parasites travel and reside. Keeping waterfowl away from your dock or direct shoreline is an action that can keep you and your family safe from lake itch.

Lake itch is not contagious; the allergic reaction cannot be passed from person to person. See your doctor if you’re uncertain whether the rash has been caused by lake itch or if it has become severe.