I had a reaction to something not too long ago. After much research and experimenting, I found that cold water, not hot, during showers eases or gets rid of a reaction on the skin

Yes...have recently been diagnosed with an allergy to petroleum based soaps and would end up with dermatitis. Now use a moisturiser based body wash and have never felt better

I break out in hives, flush feel lightheaded to hot water. I was diagnosed after suffering with heat sensitivity and many other sensitivities with mastocytosis.

Yes I had rashes as a child esp worse with bathing. We found my allergist at national Jewish health. They discovered it was due to medication I was perscribed. I am allergic to eurethromiacin. So it is likely something not related to bath time. They must ask you many questions to determine what causes the hives. Also warm water on the skin does irritate hives more because it relaxes and hydrates the skin. They may tell you to avoid frequent bathing and recommend wash cloth cleansing to keep clean but minimize soaking. I have much experience with euticaria (hives). It's very tricky to determine multiple environmental triggers.

My daughter had that issue and the doctor subscribed a cream worked wonders