What Does An Itchy Red Rash On The Stomach Indicate?

I have an itchy red rash that s been on my stomach for the past 5 days. I haven t changed any of my soaps or laundry detergents so I m puzzled to know why I m having this. The rash burns when I scratch it n gets hot even when I lightly touch it. I haven t eaten anything different either. It seems to get better when I take an allergy medicine but after taking the meds I get tired n my mouth gets dry. Before the rash I was having migraines n headaches more than usual and was getting dizzy and nauseous quite frequently. I try and wash my hands often but even if I don t and I touch my stomach to my face nothing happens. That s great cause it isn t spreading just a red burning itchy mess on my stomach.