What Causes Rashes On The Face And Shoulders While On Lamotrigine?

Hi. My 13 year old daughter is being treated for bipolar depression. She has been taking Lamotrigine 25 mgs, oral, non-time released for about 3 - 4 weeks. We saw immediate positive results. Her doc advised us to monitor skin for signs of rash, that can be severe if result of medication, occuring in 1% of population. It appears that she has developed what looks like a rash on her face and upper left shoulder. After monitoring throughout day, face area is starting to peel. Though there is some redness, it looks more like wind burn. We are having severe inclement weather in our area. My daughter was outside for an extended period of time with no hat and exposed bare face just before redness developed. I m hoping wind burn is cause and not rash from the medicine. Still, this does not account for the dryness on her upper left shoulder which was covered. I have photos of affected areas if there is anyway to send them. Being able to see what true rash actually looks like would help make comparison. Due to severe whether and overbooked medical practices, I m unable to get in to her regular doctor, or any other at present. Since the medication is effective, I really don t want to stop dosage unless necessary. Thank you vry much.