Swimmer's Itch

July 8, 2021

Manitoba beaches and lakes are being used more than ever this summer. We have some amazing beaches in our province, however at certain times a fun day of swimming can lead to a significant itch. Swimmer's itch, hives or the "itch" is a temporary itchy rash caused by worm-like parasites. These parasites are called schistosomes (shiss-toe-soams). They are found in lakes and ponds in the summer months, usually when the weather and water temperature warm up.

These parasites spend their life cycles in the bodies of water snails and in the blood stream of aquatic mammals, ducks, and other waterfowl. As the parasite larvae leave their snail hosts, they swim to the surface of the water looking for a bird or mammalian host. That host can be swimmers enjoying the beach. If the larvae get on your skin while swimming or wading in the water, they burrow under your skin. The good news is they cannot survive in in humans and die almost immediately. However, the bad news is even when they die, they cause an immune reaction, which leads to the itch.

As the larvae burrow into the skin a tingling sensation may develop, turning into an itch and red rash. Symptoms of swimmer's itch usually develop in about 12 hours and have a broad range from a mild irritation to an itchy red rash. Scratching, which is tough to avoid in children and in severe cases can cause further skin irritation and even infection. Severity is also determined by how many larvae can get in the skin and your immune response to them. Symptoms are also reported to be worse from repeated exposures because the immune system develops and stronger response. They usually last anywhere from two to five days; however, cases are reported to linger for up to 14 days. If you are golfing or hiking and swimming, be sure the rash is not from an irritating plant leaf like poison ivy.

Young children are often at highest risk of getting swimmer's itch. Kids are usually in the water all day, constantly wet while playing. They are usually also wading in shallow water, where the parasite is most likely to be. Kids also have more sensitive skin.

The only way to fully prevent swimmer's itch is to stay out of the water completely. That is not the answer you are looking for, but you can take some precautions. First, find out if the itch is being reported in the bodies of water you play to splash around in. Facebook is great, if people are getting the itch, you will likely hear about it on social media channels. Also avoid areas with lots of weed growth. Some beaches also post official warnings or bulletins. Avoiding weedy shorelines can help as snails and larvae also grow in these places. Once you leave the water, shower off well, or at least dry off immediately.

If you develop swimmer's itch some treatment options are available. Calamine lotion is inexpensive, safe for all ages and somewhat of an effective topical treatment. Antihistamines can be used to decrease the immune response. For over the age of two, liquid and pill formulations are available. Non drowsy formulations still work quickly and are preferred. Examples of these include loratadine and cetirizine. Applying cool compresses rather than scratching irritated areas is beneficial. Lukewarm baths with baking soda, Epsom salts or colloidal oatmeal baths may also help. You must avoid scratching as much as possible. A mild topical steroid could be used on red areas, but the skin should be intact and not compromised.

The information in this article is intended as a helpful guide only. It is not intended to be used as a substitute for professional advice. If you have any questions about your medications and what is right for you see your doctor, pharmacist, or other health care professional.

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