Rainbow Springs...one of 7 springs in Florida that are causing a "mystery illness"

"...Until state officials can get to the bottom of the mystery, Stevenson said, "if I was prone to allergies, I would be careful about swimming in these springs."

The reports of swimmers with rashes came from Wakulla Springs, Ichetucknee Springs, Wekiwa Springs, Rainbow Springs, Fanning Springs, DeLeon Springs and Blue Spring in the state park system. State records also show one incident that involved a snorkeler at Alexander Springs in the Ocala National Forest...." St. Petersburg Times Article