ladies ladies, i am the answer to your prayers. i KNOW what is wrong with your faces! i have it too! im not really sure what the connection is with pregnancy, but i have it now and had it before with my daughter. if you have what i have, it is called perioral dermatitis, which basically means rash around the mouth. dermatitis is a totally general term that encompasses all sorts of skin issues. but lets cut to what everyone cares about, how to get rid of the awful thing.
DO NOT use steroid cream like cortisone or anything of that sort bc it will look like it has gone away and come back with a vengence bc you have weakened your facial skin's ability to fight by itself. when the steroids go, it gets worse. not good. it is a fungal issue, not an infection, so antibiotics dont work either. olive oil has natural antifungal properties, so use that asap, and i think you will notice a difference right away. in the mean time, get some calendula flowers, which are wonderful for every sort of skin issue and infuse olive oil with them by filling a clean dry jar with the flowers and topping it off with olive oil (available at most co-ops and health food stores, not whole foods, generally). it will be ready in about 6 weeks. i basically rub it on my face as much as possible, causing my glasses to slip off and me to look a little shiney, but its better than dry and scaly, in my opinion. i would make the oil yourself, as opposed to getting a product like weleda, as theirs seems to be more cosmetic and probably has less of the herb. i would also drink nettle infusion, which is great for the skin, but is also one of the most beneficial preg tonics you can find. if you want me to tell you how to make it or where to find it, just ask.
you can also get a prescription for antifungal cream, my doc gave me ketoconizole, or something like that, and it works, however slowly, and it smells a little oniony, for some reason (your choice, oniony, scaly or greasy). i use it with olive oil and if finally went away, but came back again. go to your derm again and ask about perioral dermatitis. it may come with pregnancy bc of hormone fluctuations or immune system strain but not many derms may know that much about our "woman problems".
good luck and i hope it works!