Answer to Case 725

 Answer to Parasite Case of the Week 725: Swimmer's itch

As noted by Florida Fan, this is "typical swimmer’s itch, also known by other names depending on the activity of the patient like 'clam digger’s itch' or 'duck itch'." (Also called Pelican itch in Australia) "All are caused by [zoonotic] cercariae in most freshwater bodies of water frequented by ducks and/or water birds. The cercariae penetrate the skin and cause a cercarial dermatitis. This summer is so hot even in the Northern most states that a quick plunge into the lake is certainly very appealing. We may expect to see more cases like this one."

Indeed, this is a distressing result from what would otherwise be a lovely dip in a cool lake! 

An anonymous reader elaborated that "Swimmer's itch is an allergic condition that occurs when trematode cercariae, the motile and infectious stage of avian schistosomes (eg, Trichobilharzia spp.), penetrate the skin of humans. They utilize a variety of different species of birds as definitive hosts (humans are not suitable hosts), and rely on different snail species as intermediate hosts. If any, only symptomatic therapy is needed (anti-itch lotions, antihistamine), the cercariae die quickly without causing a severe trematode infection."

Marc Couturier noted "Growing up in Maine, we just called that...the result of swimming in Maine". Yikes! It's also common in northern Minnesota and Wisconsin in the United States.

I had to laugh at the Twitter (X) response from That Packer Girl 🏈 (@thatpackergirl) - "*sideyes the mergansers and snails at the family cabin*"

In the United States, swimmer's itch 'season' is mid summer. According to a post from Anoka County, Minnesota, Parks and Recreation,  you can "Reduce your chances of getting severe swimmers’ itch by following these simple guidelines. Dry off as soon as you leave the water. Rub skin briskly to remove water drops before they evaporate. Be sure to dry underneath waistbands and around leg openings. Encourage children to dry off thoroughly each time they leave the water. Shower with soap and fresh water or change into dry clothes as soon as possible. Don’t wade or play in shallow water. Swimming from a raft or pontoon minimizes your exposure. Don’t feed geese and ducks near your beach. Waterfowl are an important adult host for the parasites."

I hope you all enjoy the rest of the summer!