Mosquito like bumps swelling after going in water

[bissha2001]

Every time I go have a shower, or go in the pool or go to the beach. These mosquito like bumps start to raise up and starts to swell, like a mosquito bite. I know it can't be anything I use on my skin because this only started a few months ago. I tried bodywashes and soap but none of them stop them. I think they might be hives. They are always in the same spot as well. Some of the bumps don't show today and tomorrow the bumps will be there in the exact same spot. They appear on the insides of arms and on my chest and back. They itch and when I towel off, they swell even more. They only last for a 1/2 hour though, then it will ease down and disappear so I can't really even see a doctor. Is there anything I do for it at all? I'm 15 and male if that matters at all.