What To Do For The Blister In The Hands?

I broke out in red blisters all over my hands about 2 days ago. There are a few on the back of my hands but the bumps are mostly on my palms. They are spread out and become more red and irritated after showering or washing my hands. The bumps don't itch at all but they hurt when I open and close my palms. I think I've had the same thing on my feet several times and maybe once on my hands but it goes away by itself after a while. It usually occurs in the summer so I thought it might have something to do with sunlight. Someone suggested that it might also be hand, foot and mouth disease because it looks just like photos of it but I've looked up symptoms and I've never had it in my mouth and I don't feel sick. I also looked up dyshidrotic eczema because it sounded like that might be a possibility but my blisters look different from most of the pictures and they're never cracked or open. These blisters on my hands don't itch at all but the ones on my feet usually do. If you have any ideas of what this might be and how to treat it, please let me know. I am female, age 21, height 5'2, weight 120 lbs.