I was in a clinical trial for lamictal and the doctor who ran the study re-starts lamictal after the rash unless some criteria aren't met. I don't remember them now (although I was not allowed to try a re-start by his criteria so I'm thinking proximity to mucus membranes? I had the rash on my mouth and eyelid) but my understanding is that his recommendations are typically followed since he is an expert on lamictal. But my rash was a long time ago (10 years almost) and the trial was 15 years ago so it all may have changed.