Hello,
I had the same issue for a few weeks. I kept thinking a misquito got into my house and bit my all over my legs. LOL . Then my husband told me there were no misquitos, and I probably had hives. I took some benedryl and they went away. I ended up having H-Pylori as doctornee medical listed above. I took antibiotics for 2 weeks and havnt had any symtoms since. Have you doctor test you for that, if it's not that then try an allergy test.
Hi
Welcome to the forum!
Night rash could be due to contact allergy with either linen or mattress or something on the bed, even bed bugs. You can air the linen and mattress and see if that helps.
The other possibility is some food intolerance as you also have stomach problems.
If you are having acidity then the rash can be due to Helicobacter pylori bacteria. Antibiotics given to clear up the bacteria also take care of the hives.
Please consult a gastroenterologist and an allergy specialist for this.
Hope this helps. Please let me know if there is any thing else and do keep me posted. Take care!