Does anyone know anything about HIVES?

I have noticed skin sensitivity this past year and I switched everything to chemical free, like cleaners, laundry detergent, bathroom products. I was laying in bed trying to fall asleep when I noticed I was sooo itchy and I felt my thighs/calves and I was completely broken out in hives. I have no idea what to do or what could’ve caused this. I was hoping someone might have similar issues and would know what to do. Both of my thighs feel swollen and it spread all the way to my lower calves. I edited these pics to make them as decent as possible but I’m sorry if they show to much! Thanks in advance. Also no I did not shave today or even yesterday so they aren’t razor burn bumps. These came out of no where