I am on Lamictal, have researched this question and talked to my psychiatrist about it. It is extremely rare to develop the rash.
http://www.psycheducation.org/depression/meds/LamRash.htm
Yes this has the specific information on it but you should discuss it
more with your psychiatrist. As I remember when I was on Lamictal I was told by my psychiatrist that the risk decreases markedly over time but you could discuss this as well.