No way to be sure.

But it could be that the towels you are using (at your hotel in Florida) were washed with some harsh detergent that is not being thoroughly being rinsed during the laundry process.

It could be the water softener, but that seems unlikely to me.

Where on your body are the hives appearing?

I doubt it’s the softner, but I’d never say it’s impossible. Lots of places use softners, it’s unlikely you have never showered in a place with a softner before. West FL (Tampa area especially) and some other regions of FL, and parts of OH, actually most of the upper Midwest, western MD, many states have very hard water, and softners help save the plumbing and the money and toil of cleaning up hard water problems.

Any other time in your life this has happened? Hives often happen from stress, but you could be having some sort of allergic reaction. Maybe the soap or shampoos? Is it happening mostly on your upper body? Shoulders, chest, back? Top of your head itchy?

I got a crazy rash all over my body one day and the first question from my doctor had was if I had changed soap or shampoo. It was bad enough I was pulled out of school and rushed to a doctor.

Turns out is was Toaster Strudels. Like pop tarts but you spread the frosting on after you warm it up. Something in those gave me a full body rash in 30 minutes. Being a stupid 16 year old I wanted to confirm this and ate them again a few weeks later to see if they were indeed the source. They were and my sister still makes fun of me for trying again since it was really painful.

So yeah, they put so many odd chemicals into everyday shit you buy it could be anything. Soap or shampoo seems like the logical place to start.

And I am allergic to nothing except Toaster Strudels.

@johnpowell Wow! I wonder what it is in that product that you are so allergic to? Good point that it can be from any sort of allergy, not just a contact dermatitis.

I wonder if it might not be the shower, but rather something he is eating for breakfast, if the OP is doing both in the morning?

There is tons of things from soap, shampoo, the detergent used for the sheets that could be the cause. If they are staying in hotel they are probably using the cheapest shit they can buy to do laundry. And they probably keep looking for the cheapest so one rash free visit won’t result in the next visit being the same.

When you wash 500 sheets a night you buy cheap stuff.

If it was on the sheets he would wake up bad. Probably, in the middle of the night. I assumed the OP is staying with friends or family. How would he know a hotel updated their softeners? If he is drinking tap water he is drinking that same water, I would think he would be ill from it if it’s the water.

Good advice here to look at all allergens. My husband got hives after eating waffles containing Lupin flour.

Some people are allergic to Titanium and it is used in soap to make it a lighter shade.

Could definitely be detergent, soap, shampoo, body wash, etc. So if you did use something new while there, avoid it. If it keeps happening, contact your doctor and ask for an allergy scratch test. That’ll eliminate a lot of common possibilities.

I broke out with hives all over my body two different times once, but the cause could never be determined. Something that helps a lot is taking a bath and adding baking soda to it. It really cuts down on the itching and makes the welts go down.

My guess is the soap.
I am allergic to many soaps, and I have to be careful which brand I use. The gentleness of the soap has nothing to do with it.

Hm. The hives appear on my shoulders, upper arms, and upper chest. Past hives seem unrelated – as a kid I had a touch of cold-induced urticaria but I haven’t experienced a reaction to cold water in many years. Plus the showers were not cold.

I’m staying with family, so no cheap sheets or laundry detergent – in fact, they use the stuff I grew up with. After this started I assumed it was the different soap and went out and bought a bar of Dr. Bronner’s, which is what I always use at home and has never irritated my skin. I usually get the peppermint but I got Baby Unscented this time.

It could be something I ate, I guess…except that I hadn’t been eating the same stuff for breakfast, nor at the same time each morning. The only consistent thing seems to be the shower, I think…

@johnpowell That’s crazy! Toaster strudels; who’da’thunk.

Thanks for all your advice guys! I am back home in Mass now so we’ll see if it keeps happening.

I think it’s likely shampoo or conditioner, because of where the hives are. Are those different brands than usual?

It could be something in the water. As you said, “has bad water” it may be something that people used to purify it.