While a dip in the local lake is a perfect remedy for the summer heat, swimmers should be aware of the potential for swimmer's itch—a pesky rash caused by parasitic larvae that can leave a lasting impression.
Swimmer’s itch is a rash caused by an allergic reaction to larvae of certain parasites. The severity of the rash can vary for each person even if exposed to the same parasite. It may appear as itching or a burning feeling on your skin. Bumps on the skin can show up within minutes or could take a couple of days to appear after being in the water. These bumps may later change to blisters.
“The parasite can get under one's skin when we swim in freshwater such as lakes and ponds,” said Dr. Stanley Enebeli, medical health officer with SHA.
However, swimmer's itch cannot be contracted at a pool as the chlorination impacts the parasites negatively.
“The tiny parasite infects birds or mammals, and their droppings, which contain the eggs, get into lakes and ponds,” explained Enebeli. “So the eggs hatch into larvae which then infect snails surrounding the lakes and ponds.”
As the larvae are released into the water, they will seek a host. “If these larvae come into contact with people while swimming, the parasites can burrow or dig under the skin, triggering an allergic reaction that leads to the rash.”
The larvae are unable to survive in humans, so the parasites die. As a result, the rash will typically resolve on its own within a couple of days. Swimmer’s itch is not spread from human to human.
For the best chance of avoiding swimmers rash, Enebeli has a few suggestions.“Do not swim there or wade in marshy areas where snails are commonly found, and dry or shower immediately after leaving the water: He reminded the public to avoid attracting birds to the area by feeding them. This is especially true in areas where people are swimming.
While swimmer’s itch usually clears up on its own, itching the affected area could lead to additional problems.
“Scratching the rash could lead to secondary bacterial infections if the itching is severe.” He noted that if it does get to this level, seek treatment from a healthcare provider.
Before it gets to that level there are some home remedies to soothe the rash:
- use a cool wet cloth or compress on the irritated skin,
- apply anti-itch cream or calamine lotion,
- add a handful of oatmeal, ground to a powder, to your bath or use an oatmeal bath product to help relieve the itching.
Enebeli urged the public to adhere to any signs posted at the beach, such as "do not swim" or "unsafe water" warnings.
SHA has water quality monitoring for beaches across the province that look at bacterial contaminants and parasites.If the water exceeds the provincial standards or guidelines following assessments, a beach advisory will be issued.
"I would just encourage residents and visitors to check the Healthy Beaches web page as part of their pre-trip preparation and should also adhere to beach advisories."
You can read more about the Healthy Beaches app here.