Utah hikers develop parasitic infection after dip in hot spring – here's how to avoid it

Woman bathing in hot spring in forest
(Image credit: Getty)

A hiker from Utah has shared a cautionary tale after he developed a nasty case of swimmer's itch following a dip in a hot spring on a popular trail. The man, who asked not to be named, warmed himself up in Fifth Water Springs in Spanish Fork Canyon. Around a week later, he noticed an itchy rash on his body that resembled mosquito bites.

The springs are a popular place for people to soak, and visitors often switch between pools to enjoy bathing at different temperatures. They are busy all year round, and according to Utah.com, the hard packed snow makes them easy to reach in winter without snowshoes. Some even choose to bathe nude, despite it being illegal.

"Over the course of about three weeks the rash moved all around my body. (It), was very itchy and painful, causing lack of sleep, embarrassment, scars, etc," the hiker told local news site KUTV.

He visited several doctors including a dermatologist, who determined that he had picked up a parasitic infection known as cercarial dermatitis, hot tub folliculitis, or swimmer's itch. 

The rash and itching is caused by an allergic reaction to tiny parasites that burrow under your skin. The parasites normally live in waterfowl and some mammals (including beavers and muskrats). Humans aren't a suitable host, so the parasites tend to die off within a few days, allowing the rash to clear up. According to the Centers for Disease Control and Prevention (CDC), it happens most commonly in summer and most cases don't require medical treatment.

Avoid the itch

Many other hikers on AllTrails have shared similar experiences after visiting the springs in recent months. "I’ve been here many times and it’s a great hike and soak," wrote visitor Ariel Brown. "However, I hiked on 10/26 and have broken out into a rash/hives/bites. I’m not sure what it is and don’t have the insurance to get it checked.

"It’s now 11/14 and I’m at the worst point yet where it has consumed the lower half of my body and is spreading to my arms. It’s insanely itchy so soak at your own risk! "

It's wise to always check writeups of swimming spots before visiting. Mayo Clinic advises avoiding locations where swimmer's itch has been reported, or you see signs warning of possible contamination. Avoid swimming in marshy areas, and aim to move out to a deeper area of water away from the shore if you're a confident swimmer.

Applying waterproof sunscreen before taking a dip may deter parasites, and make sure you rinse off thoroughly in clean water after getting out (our guide to the best camping showers might be useful). Dry yourself off thoroughly, and launder your swimsuits regularly.

Cat Ellis

Cat is the editor of Advnture, She’s been a journalist for 15 years, and was fitness and wellbeing editor on TechRadar before joining the Advnture team in 2022. She’s a UK Athletics qualified run leader, and in her spare time enjoys nothing more than lacing up her shoes and hitting the roads and trails (the muddier, the better), usually wearing at least two sports watches.