I develeoped a rash about 16 weeks and I have come to the conclusion that it was the prenatal vitamin I was taking. Mine was a itchy rash though.. I would wake up in the middle of the night scratching like crazy. Any new items being used? Shampoo. Soap. Detergent? Lotion? I just kind of eliminated things it could potentially be. Ice and benadryl helped. Hope you feel better soon.
The only time I get rashes is when I eat Ginger (I'm allergic)... But my rash always starts on my stomach, then neck, then face... Then my tongue swells up. And it spreads from there if I don't take benedryl. So... Maybe you ate something that pregnancy triggered an allergic rxn to. In any case, callvyour doc or midwife asap. Even a simple allergy can be life threatening.
I'd call your doc asap...have you had a fever? I'd do I'd go to the er, better to be safe than sorry!