My son got a horrible skin infection from the pool here over a year ago that we are still fighting. Our doctor said it's common when pools aren't maintained properly and we were the 3rd family in months that had come to see him with that same rash. This was the only pool he was at as it was during a birthday party that was held there in the winter and he had not swam anywhere else.
My nephew also ended up with this same rash at roughly the same time from the same pool and it wasn't until I was babysitting him months later that I noticed his rash was by his armpits. After my sister and I exchanged notes it was obviously from that pool as she lives in the area and frequents it.
It needed some pretty aggressive and expensive meds to get rid of my nephews rash but my son did not respond to them and now we are removing them 3-4 at a time with laser treatment (on his neck and face mind you) out of pocket!
It's quite contagious although harmless, looks gross. And it could have been easily avoided if the chemicals in pool were properly maintained. It's called molluscum contagiosum and trust me, you don't want this bc it could take years to clear up on its own :(
Never again.