It doesn’t matter if you are at an ocean beach or swimming in a fresh water lake, if there are infected birds or mammals and the suitable snail there could be parasitic larva in the water that could burrow in your skin.
Swimmer’s itch is caused by the larvae of a parasite called schistosomes. A number of birds like ducks and gulls and some mammals like beavers can be infected with the parasite in their blood.
*These schistosomes are not the same as the ones that cause schistosomiasis in many parts of the world.
So how do these parasites get into the water that I swim in? If the feces of these infected critters find there way to water, the parasite’s eggs found in the feces will hatch releasing free-swimming larvae which in turn search for a specific species of snail.
If the right snail species is present in the water and the larvae find it, the larvae penetrate the snail to continue its life cycle. Swimmer’s itch is also called cercarial dermatidis because the next stage of the parasite, the cercariae, is released from the snail looking for its final host (bird or mammal mentioned above) to complete its life cycle.
However, sometimes the cercariae instead penetrate the skin of a human and cause a rash and an allergic reaction.
Because humans are not the appropriate final host for the development of the parasite, the cercariae will die in about a week without further disease.
The symptoms of swimmer’s itch may include tingling or itching of the skin, blisters or small pimples. These symptoms typically last about a week and gradually go away.
Scratching the affected skin should be avoided since it can result in secondary bacterial infections. Looking for a job in health care? Check here to see what’s available
The following recommendations will help reduce your chance of getting swimmer’s itch:
1. Do not swim in areas where swimmer’s itch is a known problem.
2. Do not swim near or wade in marshy areas where snails are commonly found.
3. Towel dry or shower immediately after leaving the water.
4. Do not attract birds (e.g. by feeding them) to areas where people are swimming.
Swimmer’s itch rarely requires medical attention and the itch can be relieved by using Calamine lotion, cool compresses, bathing in Epson salts and the use corticosteroid creams. For more infectious disease news and information, visit and “like” the Infectious Disease News Facebook page