Mystery Rash?? Please Help?!

Mystery Rash?? Please Help?

My mom has had this rash for a couple of years now. It happens in the pool. She first got it in her friend's salt water pool on the back of her arms. She thought it was from the rubber floaties. She covered them and it healed. Then we got a new pool guy for our chlorine pool and it broke out all over. It only shows up on her back, back of her arms, and back of her legs. Basically areas that aren't tanned or exposed to sun. We just got back from vacation where she got it from a salt water pool. It looks like red inflamed hives. Sort of like the before pictures of a person with small pox. They are very itchy and she uses Cortaid on it. Recently, they have started come with blisters on the back of her calf. One burst and started to bleed. She's been to a couple of doctors and they couldn't find what caused it or what she had allergies to. Nothing cures it. Only staying out of the pool. I was just wondering if anyone has had it or if it sounds familiar?? Thanks.

1 week ago
She also got it horribly from soaking in the bath tub.

she should find out which type of chemicals each person/place uses in their pools and what chemicals are put into the water where she took the bath
if she got it in the tub it could have been residue left over from showering after one of you swimming in the pool but it sounds like it could be chlorine because she did get it from the bathtub...if she finds out what type of chemicals each uses she can do a process of elimination to find out exactly what it is she is breaking out from