Rash on 6 year old from a life buoy by a swimming pool. Any ideas how to help treat it?

My little guy used one of those old fashioned life buoys when he swam in the pool today. He got a rash from it after about 15 minutes. Is this just a friction rash? Could it be an allergic reaction from what it is made out of, or perhaps the concentration of pool chemicals dried on the surface? It is very painful and this mommy is just beside herself with sadness that he´s woken up in pain tonight. I put some first aid cream on it and gave him a non-asprin pain reliever.

I am hoping that he wakes up feeling better in the morning, but if not, perhaps getting some sort of Lamasil or other such mild topical analgisic will help. Suggestions?