What is a Swimmer’s Itch?
Swimmer’s itch is a skin rash caused by a parasite (shistosomes) which ordinarily infect birds, semi-aquatic mammals, and snails.
Common grackles, red-winged blackbirds, ducks, geese, swans, muskrats and moles have been found to carry the parasite. As part of their developmental life-cycle, these parasites are released from infected snails, migrate through the water, and are capable of penetrating the human skin. After penetration, these parasites remain in the skin and die but can cause an allergic reaction in some people. Since a human is not their natural host, the parasite does not mature, reproduce or cause any permanent infection.
Swimmer’s itch has various other names. In eastern nations, it is often named in reference to the rice paddies where it is contracted, producing names which translate to “rice paddy itch”. For example, in Japan it is called “kubure” or “kobanyo”, in Malaysia, “sawah”, and in Thailand, “hoi con”. In the United States it is known to some as “duckworms” (in coastal New Jersey) or “clam digger’s itch”.
In certain parts of Canada, mainly Ontario, it is known as “Duck Lice” and “Beaver Lice”. In Australia it is known as “pelican itch”. In Western Minnesota, particularly on Lake Minnewaska, it is known as “Lake Itch.”
Who gets Swimmer’s Itch?
Only about one third of the people who come in contact with the parasite develop Swimmer’s Itch. People who swim or wade in infested water may experience this itchy rash. All age groups and both sexes can be involved, but children are most often infected due to their habits of swimming or wading in shallow water and playing on the beach as the water evaporates from the skin.
How is Swimmer’s Itch spread?
An individual may get the infection by swimming or wading in infested water and then allowing water to evaporate off the skin rather than drying the skin with a towel. Person-to- person spread does not occur.
What are the symptoms of swimmer’s itch?
Whenever infected water is allowed to evaporate off the skin, an initial tingling sensation may be felt associated with the penetration of the parasite into the skin. The irritated spot reaches its maximum size after about 24 hours; the itching may continue for several days. The symptoms should disappear within a week.
How soon do the symptoms begin?
A person’s first exposure to infected water may not result in the itchy rash. Repeated exposure increases a person’s allergic sensitivity to the parasite and increases the likelihood of rash development. Symptoms may appear within 1 to 2 hours of exposure.
What is the treatment for Swimmer’s Itch?
There is no treatment necessary for Swimmer’s Itch. Some people may get relief from the itching by applying skin lotions or creams to the infected site.
What can be done to reduce the chances of getting swimmer’s itch?
- Toweling off immediately after swimming or wading in infested water can be very helpful in preventing rash development.
- Swim in water away from the shore.
- Avoid swimming in areas where snails have accumulated.
- Don’t encourage birds to stay near swimming areas by feeding them.
By: BIMC Hospital