Swimming in a lake or river for ten minutes was associated with more than twice the risk of a skin rash or itching compared with standing on the shore, according to a randomized trial of 2,368 people published in the International Journal of Hygiene and Environmental Health.
The timing lands right before the last big swimming weekend of the American summer. The finding is not a reason to skip the lake, and the researchers do not frame it that way. It is a reason to understand which risk actually went up, because the headline result and the result most people assume are not the same.
