Itchy skin and bumps after a shower or bath.?

I get really itchy skin, and bumps all over my legs, and on my forearms. They kinda look like mosquito bites scattered all over my legs, and my scalp itches badly. I even tried not using any soap. And I still bust out of hives, then I researched my problem came up as "Aquagenic urticaria", but I really dont think thats what it is, because I drink water all the time. I feel fine, its only when I shower/bath. Is there away to treat this. or Prevent this so have longevity of showering, It usually occurs in like roughly 5 minutes. Hot or Cold.