10 years ago, I had a very similar situation happen to me, up in Cancun. The Pica Pica stings only had showed up on my skin, where my swimming suit had been. Unfortunately for me, I had chose to wear a one-piece swimsuit, the day I got hit by the Pica Pica. I ran into jellyfish since them, along with this past trip to AC, but I have been following a Mexican woman's advice, ever since the Pica Pica incident. Which is to liberally apply sunscreen ALL over your body, BEFORE you put your swimsuit on. Theory is the little critters get stuck inside your suit as you are happily swimming along, and for some reason, the sunscreen coats your skin and helps as a barrier. The theory seems to work. The few jellyfish stings I received are nothing compared to that awful Pica Pica body rash, which lasted a good three weeks. Good luck!! Janice